V85s 


Young 

A  Study  of  Mine  Surveying 

Methods  and  Their  Applications 

to  Mining  Engineering 


THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 


KALPH  D.  REED  UBflARY 

W>S  ANGELES.  CALIF. 


A  Study  of 

— 

Mine  Surveying  Methods 

And  Their  Applications  to 

Mining  Engineering 


L  E.  (YOUNG,  E.  M. 
Golden,  Col. 


THE  IOWA  ENGINEER 
1904 


COPYRIGHT,  1904 

BY 
L.  E.  YOUNG 


Republican  Printing  Company 
Cedar  Rapids,  Iowa 


A  STUDY  OF  MINE  SURVEYING  METHODS  AND 

THEIR  APPLICATIONS  TO  MINING 

ENGINEERING 

By  L.  E.   YOUNG 

INTRODUCTION. 

These  notes,  problems  and  observations  have  been  compiled 
in  order  to  present  in  useful  form  for  the  student  much  that  is 
today  scattered  among  various  texts  on  surveying  and  much 
from  practical  work  that  is  not  included  in  the  average  series  of 
lectures  on  mine  surveying. 

The  surveying  of  lode  and  placer  claims  has  been  omitted, 
as  the  present  methods  of  conducting  such  work  are  very  differ- 
ent from  practice  in  underground  work,  and  recent  legislation 
ha's  caused  considerable  confusion  in  all  mineral  surveys. 

Mine  surveying  is  really  one  part  of  mining  engineering. 
The  purpose  of  these  notes  is  to  show  how  mine  surveying  enters 
into  all  the  other  phases  of  mining  engineering  and  what  meth- 
ods are  best  adapted  to  each  kind  of  work.  . 

It  is  assumed  that  the  student  has  a  good  knowledge  of  the 
instruments  and  methods  of  plane  surveying.  He  should  be 
skillful  in  handling  and  adjusting  the  various  instruments.  In- 
struction in  the  art  of  adjusting  the  transit  as  used  in  mining 
work  should  be  given  before  underground  work  is  attempted 

DEFINITION. 

The  following  definition  is  included  in  the  introduction  to 
Johnson's  "Theory  and  Practice  of  Surveying":  "Surveying 
is  the  art  of  making  such  field  observations  and  measurements 
as  are  necessary  to  determine  positions,  areas,  volumes,  or 
movements  on  the  earth's  surface.  The  field  operations  em- 
ployed to  accomplish  any  of  these  ends  constitute  a  survey. 
Accompanying  such  survey  there  is  usually  the  field  record, 
the  computation,  and  the  final  maps,  plats,  profiles,  areas,  or 
volumes.  The  art  of  making  all  these  belongs,  therefore,  to  the 
subject  of  surveying." 

Mine  surveying  is  generally  defined  as  the  art  of  making 
such  measurements  as  may  be  necessary  (a)  to  determine  the 
location  and  extent  of  bodies  of  coal,  ore,  etc.,  (b)  to  determine 
the  relative  positions  of  points  in  the  mine  with  regard  to  each 
other  or  to  points  on  the  surface. 

894803 


/  A  STUDY  OF  MINE  SURVEYING  METHODS 

IMPORTANCE. 

A.  In  all  surveys  the  importance  and  the  accuracy  of  con- 
ducting the  work  should  be  directly  proportional.     The  great 
value  of  our  mineral  deposits  and  their  limited   extent  war- 
rant and  demand  the  greatest  care  in  establishing  boundaries 
and  in  conducting  underground  surveys.     An  example  of  this 
fact  is  often  seen  in  errors  in  surveying  lode  claims.     A  foot 
increased  length  on  the  line  of  a  lode  three  feet  wide  and  con- 
taining ore  worth   twenty-five   dollars   a  ton,     (fifteen     cubic 
feet  per  ton)  represents  for  each  thousand  feet  in  depth  on  the 
lode  a  value  of  five  thousand  dollars. 

B.  Pillars  of  sufficient  size  and  propertly  located  must  be 
left  in  the  mine  either  permanently  or  temporarily  in  order  to 
protect  important  passages,  to  prevent  the  inrush  of  water  and 
to  protect  adjoining  property  or  buildings  on  the  surface. 

C.  Royalties  are  often  based  on  the  underground  surveys. 
Stopes  and  working  places  must  be  accurately  measured  to  de- 
termine the  volume  of  the  excavation.     From  these  figures  the 
tonnage  removed  is  estimated. 

D.  Before  any  permanent  openings  are  made,  complete 
surveys -should  be  made  in  order  to  determine  the  most  ad- 
vantageous site.    The  best  location  for  a  shaft,  slope  or  tunnel, 
and  the  best  methods  of  exploitation,  drainage,  underground 
transportation,  hoisting,  ventilation,  etc.,  depend  on  the  knowl- 
edge of  the  deposit  given  by  careful  surveys. 

E.  In  order  to  avoid  breaking  into  old  workings,  where 
there  may  be  quantities   of  gas  or  water,  good  surveys  and 
maps  are  necessary.     Many  states  require  the  filing  of  maps  of 
mines  that  are  about  to  be  abandoned.    When  driving  openings 
towards  such  workings,  the  proximity  to  dangerous  ground  can 
be  determined  by  careful  survey. 

F.  Geological   features   and   irregularities   discovered   by 
drill  holes  or  openings,  when  properly  recorded  and  mapped, 
may  be  anticipated. 

G.  Buildings,   tracks,    reservoirs,    streams,    etc.,    may   be 
properly  protected  if  the  openings  are  properly  mapped. 

H.  Many  mine  surveying  problems  occur  that  demand 
great  exactness ;  for  instance,  to  determine  a  point  on  the  sur- 
face directly  above  a  given  point  underground,  in  order  that  a 
bore  hole  or  shaft  may  be  sunk  to  connect  the  former  with 
the  latter. 

I.  A  system  of  bore  holes  or  drifts,  an  examination  of 
samples  from  the  body  blocked  out  and  a  complete  survey  will 
permit  of  the  estimation  of  the  value  of  a  mine  or  mineral  deposit. 


AND  THEIR  APPLICA  TIONS  TO  MINING  ENGINEERING    j 

J.  Much  litigation  may  be  avoided  if  the  mine  is  properly 
surveyed. 

From  these  few  statements  the  importance  of  mine  survey- 
ing is  obvious.  An  inaccurate  survey  is  valueless,  in  fact  a  poor 
survey  is  often  worse  than  none,  in  that  openings  may  be  driven 
in  the  wrong  direction  to  make  connections,  old  workings  may 
oe  tapped,  etc.  One  of  the  essential  things  for  a  mine  surveyor 
to  appreciate  is  the  accuracy  demanded  of  him. 

DIFFICULTIES. 
Many  difficulties  characterize  mine  surveying: 

A.  The  surveyor  is  frequently  called  upon  to  carry  a  line 
through  low,  narrow  places  where  it  is  difficult  to  set  up  the 
transit,  take  sights  and  measure  distances.     Coal  seams  twenty- 
eight  inches  thick  are  frequently  mined  ;  veins  even  narrower  are 
mined  and  often  stations  must  be  established  and  surveys  made 
in  openings  not  more  than  twenty-eight  inches  high. 

B.  Artificial  light  is  necessary  in  order  to  illuminate  the 
point  of  sight  and  the  cross  hairs.     Such  light  is  generally  very 
poor,  and  this  fact  greatly  hampers  work  with  the  instrument. 
When  the  safety  lamp  is  necessary,  the  candle  power  is  reduced 
to  less  than  unity. 

C.  A    smoky    atmosphere    greatly    reduces    the    possible 
length  of  sight  and  often  compels  the  surveying  squad  to  post- 
pone the  survey.     Sights  of  over  two  thousand  feet  are  possible 
in  good  air,  but  when  the  powder  smoke  is  dense  thirty  feet  is 
a  good  sight. 

D.  In  surveying  highly  inclined  openings  it  becomes  nec- 
essary to  use  an  auxiliary  telescope  to  read  vertical  angles,  to 
measure  inclined  distances,  and  to  calculate  horizontal  distances 
and  differences  in  elevation. 

E.  It  is  not  always  possible  to  make  a  closed  survey,  so 
that  the  advantage  of  having  a  closed  check  is  lost.     This  neces- 
sitates repeating  angles  and  remeasuring  distances  for  all  accur- 
ate work. 

F.  The  actual  underground  conditions  frequently  necessi- 
tate the  establishing  of  stations  in  the  roof  instead  of  in  the 
floor  and  setting  up  the  transit  under  a  point  instead  of  over 
a  point. 

G.  The  survey  must  be  conducted  so  as  not  to  interfere 
with  mining  operations.     This  requires  that  the  work  be  con- 
ducted rapidly  and  at  the  same  time  accurately. 

Methods  of  conducting  underground  surveys  vary  greatly ; 
in  England  methods  are  still  in  vogue  which  have  long  since 
been  abandoned  in  America.  The  methods  in  the  United  States 
depend  largely  on  the  value  of  the  deposit  and  the  proximity  of 
other  workings. 


6  A  STUDY  OF  MINE  SURVEYING  .METHODS 

NOTES  ON  HISTORY. 

A  history  of  mine  surveying  would  be  composed  largely  of  a 
record  of  the  evolution  of  mine  surveying  instruments.  Such  a 
record  has  been  recently  compiled  by  D.  D.  Scott  and  others 
and  published  in  the  Transactions  of  the  American  Institute  of 
Mining  Engineers,  Volumes  XXVIIPXXXI.  A  few  of  the 
more  important  points  given  in  this  record  follow. 

"Mine  surveying,  in  some  form  or  other,  has  been  prac- 
ticed from  the  earliest  times ;  but  it  has  never  kept  pace  with  the 
other  branches  of  surveying,  or  even  with  the  art  of  mining  it- 
self, and  cannot  be  recognized  as  an  exact  science  until  shortly 
after  the  beginning  of  this  century." 

1556  A.  D. — Agricola,  in  his  De  Re  Metallica  describes  the 
practice  of  mine-surveying.  The  instruments  used  were  very 
crude,  the  principal  one  being  the  stationary  compass. 

1571.  Diggs  describes  the  "theodolitus,"  also  applies  the 
principle  of  the  telescope. 

1633.  Rossler  invented  the  method  of  suspending  from 
a  cord  a  compass  and  clinometer. 

1681.  Houghton  describes  the  use  of  strings,  plumbs  and 
compass. 

1686.  Geometria  Subterrania,  of  Nicholas  Voigtel  (Eisle- 
ben,  Saxony,  1686)  exhibits  slight  development  in  methods  and 
instruments  for  mine  surveying. 

1710.     Strum  proposed  the  astrolabium  for  the  miner. 

1775.     Kastner  designed  the  quadrant  clinometer. 

1785.  Beyer  describes  the  common  hanging  compass.  Tri- 
pod came  into  use. 

1798.     Breithaupt   introduced   mine   theodolites-. 

1820.     First  American  transit  manufactured. 

1843.  Bourne  first  used  high  class  theodolite  in  tunnel 
work. 

1850.  First  American  mine  transit.  Top  telescope  first 
used. 

1858.     Shifting  tripod  head  successfully  used. 

1873.  Coxe   describes   plummet   lamp   used   in   anthracite 
coal  mine. 

1874.  Coxe  describes  five  hundred  foot  steel  tape  used  in 
coal  mine  surveying. 

GENERAL  STATEMENT  OF  INSTRUMENTS  AND 
EQUIPMENT  USED. 

A.  Transit.  The  instrument  should  be  selected  with  ref- 
erence to  the  work  to  be  done.  The  regular  light  mountain 
transit,  equipped  with  auxiliary  telescope  and  mounted  on  an 


AND  THEIR  A  F  FLIC  A  TIONS  TO  .MINING  ENGINEERING    7 

extension  tripod  is  commonly  used.  For  careful  work,  the 
instrument  should  have  a  complete  vertical  circle.  A  complete 
description  of  mining  transits  is  given  in  the  volume  of  Scott 
and  others  on  "Mine  "Surveying  Instruments."  The  transit 
should  be  equipped  with  a  reflector  and  at  times  with  a  prismMic 
occular.  'U 

B.  Compass.     The  compass,  by  means  of  which  the  first 
surveys  were  made  and  which  is  still  in  use  in  many  districts, 
cannot  be  relied  upon   for  accurate  work  especially  in  prox- 
imity to  bodies  of  iron  or  iron  ore.     Lupton  in  his  "Practical 
Treatise  on  Mine  Surveying"  published  1902,  says  in  regard  to 
practice  in  English  mines:     "The  dial  is  the  instrument  generally 
used  by  mining  surveyors  for  taking  bearings  and  angles.     The 
graduated  circle  is  stationary  and  the  needle  swings  clear  of  "it. 
Dials  are  made  of  various  sizes,  from  a  small  pocket  one  up  to 
one   carrying  a   needle   eighteen   inches   long.       The   circle   is 
divided  into  degrees,  and  if  the  end  of  the  needle  is  not  opposite 
one  of  the  divisions,  the  surveyor  has  to  estimate  as  nearly  as 
he  can  the  fraction  of  the  degree  beyond  the  last  unit,  thus,  %,  %, 
%,  %,  %,  %,  and  %  ;  the  bearing  being,  say  southeast  21%°". 

However,  in  the  United  States,  the  compass  survey  is  prac- 
tically obsolete,  many  transists  being  constructed  without  the 
compass.  The  compass  reading  serves  as  a  check  to  detect  er- 
rors of  more  than  one  degree.  For  making  a  rough  plat  of  a 
mine,  the  compass  is,  however,  of  great  use.  Many  so  called 
hand  transists  which  resemble  the  English  dial  are  used  for 
making  such  plats. 

C.  Level  and  Rod.     The  ordinary  engineer's  or  wye  level 
is  used  underground   in   determining  the   elevation   of  points. 
When  the  survey  is  properly  conducted  with  the  transit,  vertical 
distances  are  measured  and  it  becomes   unnecessary  to  carry 
elevation  by  the  level.     Frequently  the  level  is  used  in  setting 
timbers,  sleepers,  machinery,  etc.     The  level  should  be  mounted 
on  a  heavy,  adjustable  tripod  for  precise  work. 

The  rod  used  may  be  the  regular  five  foot  one  which  can 
be  extended  to  nine  feet.  The  target  should  be  so  constructed 
that  it  can  be  easily  illuminated.  Johnson  suggests  that  "a 
small  steel  rod  like  a  knitting  needle  may  be  soldered  onto  the 
target  at  the  zero  line  so  as  to  project  two  or  three  inches,  then 
a  paper  and  light  held  behind  it  properly  will  enable  the  target 
to  be  set." 

D.  Tapes.     In  mine  surveying  in  the  United  States  the 
chain  is  practically  obsolete.     References  are  made  in  recent 
articles  to  its  use,  but  the  work  done  with  the  steel  tape  is  much 
more  accurate.     A  TOO  foot  steel  tape  divided  into  tenths  and 
hundredths  of  a  foot  is  most  generally  used  by  American  engin- 


8  A  STUDY  OF  MINE  SURVEYING  METHODS 

eers.  Mr.  E.  B.  Coxe  was  the  first  to  introduce  the  long  steel 
tape  or  chain  tape,  at  first  500  feet  long,  afterwards  up  to  1000 
feet.  Many  tapes,  100  feet  long,  are  graduated  to  feet  through- 
out their  entire  length  and  to  hundredths  only  from  o  to  10  and 
fom  90  to  loo.  In  the  anthracite  fields  tapes  310  feet  long  have 
brcn  used.  The  tape  is  so  graduated  that  beginning  at  one  end, 
the  marks  are  10,  9,  8,  7,  to  o  and  then  increase  up  to  300  at  the 
other  end.  Tapes  300  to  1000  feet  long  are  of  great  advantage 
in  measuring  long  sights  and  also  in  measuring  up  working 
places. 

The  length  of  tape  and  the  graduation  should  be  adapted  to 
the  work.  For  important  surveys,  especially  in  establishing  the 
base  line  and  carrying  the  meridian  into  the  mine,  a  very  good 
tape  should  be  used.  It  is  never  economy  to  purchase  a  cheap 
tape.  Errors  are  frequently  traceable  to  the  use  of  a  poor 
tape,  and  the  cost  or  re-surveying  any  portion  of  a  mine  would 
more  than  pay  for  a  good  tape. 

In  shaft  work  the  tape  should  be  of  such  a  length  that  the 
longest  sights  and  distances  can  be  measured  without  establish- 
ing intermediate  points.  A  200  or  300  foot  tape  carefully  grad- 
uated should  always  be  reserved  for  shaft  work. 

In  traversing  underground  where  long  sights  cannot  be 
made,  a  tape  .more  than  100  feet  long  is  inconvenient.  How- 
ever, -when  entries  or  levels  are  driven  straight  or  "on  line"  long 
tapes  can  be  used  to  advantage. 

For  "measuring  up"  stopes  and  rooms  long  tapes  should  be 
provided — the  length  being  determined  by  the  regular  system 
of  opening  up  the  working  places.  In  coal  mines  the  rooms  are 
frequently  from  200  to  300  feet  long.  In  metal  mines  the  levels 
are  seldom  more  than  200  feet  apart  and  the  stopes  are  there- 
fore limited  to  200  feet  in  height.  These  tapes  need  not  be 
graduated  more  than  to  feet. 

Pocket  tapes  of  10  to  25  feet  lengths  should  be  carried  by 
the  instrument  man  and  the  man  who  takes  the  side  notes.  The 
instrument  man  must  measure  the  height  of  instrument  and  of 
the  point,  and  should  have  a  tape  reading  to  hundredths.  In 
taking  side  notes  it  is  generally  not  necessary  to  measure  closer 
than  the  tenths  of  a  foot. 

The  standardizing  of  tapes  is  very  important.  If  no  stand- 
ard is  within  easy  access  of  the  mine,  the  tapes  should  be  sent 
at  regular  intervals  to  some  instrument  maker  to  be  compared 
with  the  standard.  In  repairing  tapes,  it  is  very  difficult  to 
restore  the  proper  distance  between  graduations  on  opposite 
sides  of  the  break.  It  pays  to  send  good  tapes  when  broken  to 
those  who  make  a  business  of  repairing  tapes. 


A\D  THEIR  APPLICA  TIOXS  TO  AIIXIXG  EXG1XEERIXG    9 

Mine  water  frequently  attacks  tapes  locally,  thus  causing 
a  reduction  in  the  cross-sectional  area.  The  tape  hence  becomes 
weaker  at  such  points  and,  if  it  does  not  break,  will  stretch 
considerably  if  subjected  to  much  tension.  Such  elongation 
can  be  detected  only  by  comparison  with  a  standard. 

Provision  should  be  made  for  repairing  a  broken  tape  with- 
out returning  to  the  surface.  Various  types  of  clips  or  splices 
can  be  made  for  this  purpose,  or  can  be  obtained  from  instru- 
ment companies.  Such  precautions  may  save  considerable  de- 
lay. 

Cleaning  the  tape  is  very  necessary  if  the  tape  is  to  be 
used  in  a  mine  producing  acid  water.  Most  mines  produce 
enough  water  to  coat  a  tape  with  mud  if  the  tape  is  not  held  off 
the  ground.  Acid  water  if  not  speedily  removed  will  soon 
weaken  the  tape,  and  render  it  unfit  for  accurate  work.  Grit 
and  mud  will,  by  abrasion,  injure  the  tape  in  several  ways.  The 
graduations  will  soon  be  worn  away  and  the  coiling  of  the  tape 
on  a  reel  will  give  the  grit  opportunity  to  grind  out  deep  notches. 
The  tape,  then,  must  be  carefully  cleaned  either  underground  or 
on  the  surface.  A  preliminary  cleaning  should  be  given  under- 
ground, but  this  should  always  be  succeeded  by  careful  work  on 
the  surface.  One  end  of  the  tape  should  be  attached  to  a  fixed 
point  several  feet  above  the  ground  and  beginning  at  the  end  so 
attached,  the  operation  of  removing  the  dirt  and  wiping  dry 
should  proceed  to  the  unattached  end.  After  the  tape  has  been 
wiped  drv.  it  should  be  rubbed  with  oil.  Common  kerosene 
is  generally  used,  but  this  is  hardly  of  benefit.  Sperm  and  olive 
oil  are  recommended. 

Reels  of  various  types  are  used  in  mining  work.  It  is 
advisable  to  keep  the  tape  out  of  the  water  and  mud.  and  when 
not  in  continuous  service  it  is  advisable  to  reel  up  the  tape  and 
thus  preserve  it.  Such  reels  may  be  of  wood  or  metal,  and 
should  be  so  constructed  that  the  tape  can  be  wound  up  without 
binding,  even  when  heavily  coated  with  dirt.  A  convenient 
form  of  reel  is  made  of  steel,  of  such  design  that  the  tape  winds 
on  itself;  across  the  back  of  the  reel  is  a  leather  band  or  holder 
through  which  the  left  hand  is  passed.  Holding  the  reel  in  the 
left  hand  the  chainman  easily  winds  up  the  tape  by  means  of  his 
right.  Care  should  be  taken  in  removing  the  tape  from  the 
reel  as  carelessness  will  result  in  breaking  the  end  off  the  tape. 
It  is  advisable  to  carry  the  tape  into  and  out  of  the  mine  on  a 
reel. 

Metal  handles  or  clamps  may  be  attached  to  the  ends  of  the 
tape  or  points  intermediate  in  order  to  facilitate  measuring. 
Many  engineers  attach  leather  strips  to  the  ends  of  tapes  instead 
of  using  the  metal  handles.  In  order  to  have  uniformity  of 


10  A  STUDY  OF  MINE  SURVEYING  METHODS 

tension  in  chaining  spring  balances  may  be  used.  In  this  way, 
the  tension  being  known,  the  amount  of  sag  can  be  calculated. 

The  average  tape  used  in  mine  surveying  is  graduated  only 
to  feet.  Some  special  device  or  method  must  be  employed  in 
order  to  read  the  tenths  and  hundredths.  Commonly  in  chain- 
ing or  measuring  the  tape  is  pulled  up,  the  front  chainman 
marks  the  proper  distance  on  the  tape  by  means  of  his  left 
thumb,  then  reads  the  next  foot  mark  toward  the  zero  point, 
and  measures  to  his  thumb  by  means  of  a  short  auxiliary  tape. 
Instead  of  marking  with  the  thumb  a  metal  clip  may  be  used ; 
this  will  witness  the  distance  until  measured  with  the  small  tape. 

A  convenient  scheme  is  used  by  many  engineers,  by  the  use 
of  which  marking  clips  and  small  tapes  become  unnecessary.  A 
strip  of  wood  about  one  inch  wide,  one-eighth  inch  thick,  and 
about  seven-tenths  of  a  foot  long  is  prepared.  One  end  is  cut 
square  and  becomes  the  zero  end.  Measuring  from  this  end, 
tenths  are  laid  off  and  notches  cut  as  marks.  In  order  to  dis- 
tinguish the  zero  end,  the  other  end  is  rounded.  Suppose  the 
distance  between  stations  is  between  twenty-seven  and  twenty- 
eight  feet.  The  tape  is  drawn  up,  the  thumb  of  the  left  hand 
catches  the  point  on  tape  and  the  strip  of  \vood  is  brought  up 
with  the  right  hand  and  the  distance  from  the  point  marked  by 
left  hand  to  the  nearest  foot  mark  on  tape  is  measured  by  the 
stick.  The  tenths  can  then  be  easily  read  and  the  hundredths 
estimated.  This  decimal  of  a  foot  will  be  either  added  to  or 
substracted  from  the  \vhole  number  of  feet  depending  on  the 
direction  of  measurement.  The  stick  can  be  carried  in  a  pocket 
and  can  be  easily  replaced  if  broken  or  lost. 

The  zero  point  of  the  tape  may  be  several  feet  from  the 
end.  In  the  anthracite  fields  this  length  from  zero  to  the  end 
is  as  much  as  10  feet.  These  10  feet  are  graduated  regularly  to 
hundredths,  the  end  of  the  tape  being  marked  10.  From  zero 
to  the  other  end,  the  tape  is  marked  in  feet.  In  measuring  with 
such  a  tape  the  rear  chainman  first  holds  the  zero  point  of  the 
tape  at  the  rear  station  so  that  the  fore  chainman  can  determine 
the  nearest  10  foot  mark  toward  the  rear  chainman.  That  is,  he 
determines  whether  the  distance  between  stations  is  between 
no  and  120  feet  or  120  and  130  feet.  If  between  no  and  120, 
he  draws  up  the  tape  until  no  is  at  the  front  station,  he  then 
calls  "chain"  to  the  rear  chainman  who  reads  on  the  extension 
beyond  the  zero  point  the  number  of  feet  and  hundredths  which 
must  be  added  to  1 10.  Thus  auxiliary  tapes,  markers,  etc.,  may 
be  avoided. 

The  measurement  of  distances  should  be  checked  in  all 
possible  ways.  Each  party  should  measure  distances  twice. 
When  returning  through  newly  surveyed  openings,  some  mem- 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       // 

her  of  the  party  should  be  detailed  to  pace  distances  and  check 
the  measured  ditances.  When  it  is  known  that  levels,  entries 
and  rooms  are  driven  a  standard  distance  apart,  calculations 
should  be  made  underground  and  measured  distances  thus 
checked. 

E.  Bobs  an  Stations.  The  tools  and  equipment  for  locat- 
ing, making  and  marking  stations  vary  considerably  and  will  be 
described  in  detail  later.  Commonly,  plumb  bobs  suspended  from 
stations  in  the  roof  by  twine  or  wire  give  the  point  of  sight. 
Three  bobs  should  be  provided,  one  for  the  instrument,  one  for 
the  back  sight  and  one  for  the  fore  sight.  Ample  string  or 
wire  and  other  supplies  should  be  provided  for  each  day's  work. 

Miscellaneous.  Note  books  must  be  provided  for  the 
proper  recording  of  all  observations  made.  Books  should  be  so 
filed  and  work  so  recorded  that  any  member  of  the  engineering 
corps  can  find  and  plat  notes,  or  continue  the  work  of  any  other 
member.  The  notes  of  a  transitman  are  generally  taken  as  an 
index  of  his  work.  Some  field  or  pocket  book  sheuld  be  carried 
by  the  party  so  that  calculations  may  be  made  in  the  field  if  at 
any  time  a  check  on  the  work  is  desired  or  if  it  becomes  neces- 
sary to  set  points  properly  for  directing  workmen  in  driving 
openings  or  in  locating  timber,  guides,  etc. 

A  reading  glass  is  necessary  for  the  transitman,  a  sheet  of 
tracing  cloth  or  oiled  paper  for  those  giving  sights,  a  thermome- 
ter if  there  be  any  marked  increase  of  temperature  in  the  lower 
workings  of  a  mine  over  that  in  the  upper  workings  or  of  the 
surface.  Corrections  in  measurement  should  be  made  when  the 
temperature  is  high.  An  adjusting  pin,  screw  driver,  and  sim- 
ple repair  kit  should  be  included  in  the  outfit  of  a  party  which 
is  going  out  for  several  days  surveying. 

SURVEYING  PARTY. 

Number.  The  number  of  men  included  in  the  party  de- 
pends entirely  on  the  work  to  be  done,  the  skill  of  the  members, 
and  the  time  allowed  for  completing  the  work.  Often,  the 
transitman  only  is  experienced  and  must  take  as  his  assistants 
so  called  "helpers"  who  know  nothing  of  surveying.  In  order 
to  do  measuring  the  party  must  consist  of  at  least  two.  When  a 
mining  company  has  sufficient  work  to  keep  one  party  in  the 
field  continually,  one  or  two  men  may  assist  the  transitman. 
In  the  anthracite  field,  surveying  is  done  by  parties  of  seven 
divided  into  two  squads — one  consisting  of  the  chief  and  two 
helpers  who  locate  stations,  measure  distances  and  take  side 
notes,  and  the  other  party  reads  and  records  angles  and  dis- 
tances. Parties  of  more  than  four  are  uncommon. 


is  A  STUDY  OF  MINE  SURVEYING  METHODS 

Work  of  Members  of  Party.  The  chief  of  a  party  directs 
the  survey,  establishes  points,  takes  side  notes,  and  checks  dis- 
tances. He  must  be  able  to  plan  and  direct  the  work  and 
manage  men.  The  transitman  may  be  chief  of  party.  He  has 
charge  of  the  transit,  reads  and  records  angles  and  distances ;  he 
may  take  the  side  notes.  He  must  be  an  accurate  and  rapid 
worker.  Accuracy,  however,  comes  first,  as  inaccurate  work  is 
valueless. 

The  fore  sightman  or  fore  chainman  establishes  stations, 
numbers  and  marks  the  stations,  gives  the  fore-sight,  superin- 
tends measuring,  records  distances,  may  keep  side  notes  and 
may  be  detailed  to  set  up  the  instrument.  He  must  be  a  good 
conscientious  worker  and  should  take  much  pains  and  pride  in 
his  work. 

The  back  sightman  gives  backsights,  assists  in  chaining, 
carries  any  material  to  be  carried,  keeps  all  equipment  save  the 
transit  in  good  shape,  cleans  the  tapes,  makes  plugs,  etc.,  and 
sharpens  tools.  He  must  be  a  good  workman  and  should  have 
ambition  to  become  the  transitman. 

Side  notes  may  be  taken  by  the  chief  of  the  party  when  the 
party  is  divided  into  two  squads,  and  by  the  transitman  when 
there  is  but  one  squad.  If  the  fore  sightman  is  competent,  this 
work  may  be  assigned  to  him.  The  completeness  of  the  mine 
map  depends  largely  upon  the  care  with  which  the  side  notes 
are  taken,  and  such  work  should  receive  considerable  attention. 
By  side  notes  are  meant  those  additional  measurements  which 
are  taken  off  the  traverses,  by  which  points  in  adjacent  excava- 
tions are  located  with  regard  to  the  traverses.  The  dimensions 
and  location  of  openings  are  thereby  determined. 

Work  of  Party.  A.  The  success  of  the  party  depends 
largely  upon  the  chief.  He  should  understand  men,  have  their 
confidence,  encourage  them  to  learn  the  details  and  principles  of 
the  work.  He  should  be  able  to  plan  work  so  that  the  entire 
party  shall  be  busy  and  if  possible  have  his  assistants  attend  to 
all  details.  He  can  then  give  his  hill  time  to  running  the  party 
and  doing  transit  work. 

B.  A  good  party  is  composed  of  men  who  will  do  more 
than  the  actual  work  assigned  and  who  realize  the  importance 
of  the  details.     Failure  to  provide  daily  the  proper  tools  and 
equipment,  may  render  many  hours  work  valueless  or  cause 
considerable  loss  of  time  while  the  necessary  equipment  is  being 
provided. 

C.  Surveying  work  should  not  interfere  with  mining  oper- 
ations and  vice  versa.     When  properly  planned  and  executeu, 
the  work  may  be  carried  along  entries  which  are  used  for  haul- 
age   without    materially   interfering   with    traffic.     Smoke    will 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       13 

interfere  with  the  work  if  the  chief  has  not  anticipated  it  and 
transferred  his  work  .to  passages  having  a  clear  atmosphere. 
The  work  can  be  properly  planned  so  that  the  party  shall  have 
completed  the  work  in  haulage  ways  or  near  working  places 
before  cars  or  smoke  can  interfere. 

D.  Too  much  stress  cannot  be  laid  upon  the  importance 
of  subordination  of  all  other  members  of  the  party  to  the  chief. 
The  party  must  work  toge'ther.     The  chief  should  enjoy  the 
most  earnest  co-operation  of  his  men  and  should  make  them 
appreciate  that  careful  work  and  strict  attention  to  all  details 
are   necessary   to   good   surveying.     A   few   minutes   given   to 
explanation  of  the  importance  and  object  of  certain  operations 
may  in  the  end  save  much  time.     Each  man  should  be  made  to 
realize  that  his  welfare  is  being  considered  by  the  chief,  thai 
he  is  not     obliged  to  do  unnecessary  work,  or  to  remain  in 
strained  positions  an  unwarranted  length  of  time,  and,  especially, 
that  his  time  belongs  entirely  to  the  chief  of  squad. 

E.  A  complete  and  practical  system  of  signals  should  be 
devised  for  underground  work.     Systems  in  vogue  on  the  sur- 
face are  in  general  impracticable  underground.     In  sighting  and 
measuring  it  is  very  important  that  the  man  at  the  instrument 
or  at  one  end  of  the  tape  should  be  able  to  communicate  with 
his  co-laborer  without  walking  or  climbing  to  him.     The  move- 
ment of  a  light  or  special  sounds  are  commonly  used  to  indicate 
certain  orders.     However,  where  a  number  of  lights  are  con- 
tinually moving  about,  as  in  shaft  sinking,  the  use  of  the  light 
as  the  signal  is  impossible.     Again,  the  voice  or  a  whistle  cannot 
be  used  in  the  proximity  of  noisy  machinery.     Frequently  in 
doing  important  work,  especially  in  shafts,  surveyors  stretch  a 
chord  or  wire  so  that  by  movements  of  this  chord  one  party 
below  may  signal  to  another  above  or  vice  versa.     Special  sys- 
tems may  easily  be  devised  to  fit  the  occasion. 

F.  Special   care  should  be  taken  with   all  notes.     Notes 
cannot  be  too  full.     The  surveying  party  should  note  geological 
features,  character  of  mineral,  thickness  and  character  of  coal 
or  other  points  which  may  later  on  be  of  value  in  planning 
underground  operations.     It  is  much  more  economical  to  take 
full   and   complete   notes   when   making  a   survey  than   to  be 
obliged  later  on  to  make  a  special  visit  to  determine  these  points. 
By  noting  faults  or  horses  in  the  upper  workings,  these  can  be 
frequently  anticipated  in  driving  lower  or  adjacent  openings. 
All   readings  and   measurements   should   be   checked  as  often 
as  possible.     Subordinates  should  be  trained  to  check  readings 
for  the  instrument  man.     The  foresightman  should  carry  a  note- 
book and  record  measured  distances  even  though  he  do  not 
take  the  side  notes.     Many  calculations  may  be  made  in  the 


//  A  STUDY  OF  MINE  SURVEYING  METHODS 

field  to  check  observations  without  interfering  with  actual  work. 
Frequently  a  few  minutes  spent  in  this. way  will  save  several 
hours  work  in  correcting  errors  or  making  resurveys. 

'    UNDERGROUND  STATIONS. 

The  care  with  which  a  station  should  be  established  de- 
pends upon  the  character  of  the  survey  and  whether  or  not  it  is 
to  be  considered  a  permanent  station.  Stations  may  be  divided 
into  two  groups — (a)  temporary,  and  (b)  permanent. 

By  a  temporary  station  is  meant  any  station  which  will 
probably  be  knocked  out  soon  after  being  established  or  one 
which  is  designed  to  serve  only  for  the  survey  for  which  it  is  put 
in.  A  permanent  station  is  established  carefully  and  precautions 
are  taken  to  have  it  so  located  and  marked  that  it  may  serve 
with  similar  points  as  a  base  or  reference  10  vhich  subsequent 
surveys  may  be  tied. 

The  inexperienced  surveyor  loses  more  time  by  making 
poor  stations  and  by  marking  them  in  a  poor  manner  than  by 
making  actual  errors  in  the  survey.  The  surveyor  whose  work 
it  is  to  keep  a  shaft  or  tunnel  properly  aligned  or  to  keep  the 
mine  man  up  to  date  should  before  beginning  a  survey  check 
up  his  newest  stations  to  see  that  they  have  not  been  disturbed. 
Very  often  the  station  mark  has  been  removed,  the  station  has 
been  tampered  with,  is  inaccessible  or  has  dropped  out  or  been ' 
completely  destroyed.  The  experienced  surveyor  sees  that  he 
has  a  number  of  stations  so  established  that  even  though  one  is 
destroyed,  he  suffers  no  great  inconvenience. 

i.  The  permanency  of  a  station  in  the  floor  or  bottom 
depends  upon  (a)  the  marking,  (b)  the  character  of  material, 
(c)  the  hardness  of  ties,  (d)  the  amount  and  kind  of  haulage,  (e) 
the  character  of  the  roof,  (f)  the  character  of  the  station  it- 
self or  (g)  the  mine  water. 

a.  In  all  cases  the  station  which  cannot  be  indentified  is 
worthless.     To   be   of  value   or   permanent   the   station   in   the 
floor  must  be  so  marked  that  it  can  be  easily  found  and  identi- 

b.  A  permanent  station  cannot  be  established  in  the  floor 
when  the  latter  is  composed  of  very  soft  material ;  or,  when 
there  is  considerable  pressure  about  the  opening,  the  floor  mater- 
ial is  forced  up  thus  displacing  the  station. 

c.  Frequently    stations   are    established    in   the    ties.        A 
station  in  soft  wood  is  practically  valueless  as  a  permanent  mark 
for  it  is  easily  loosened  or  displaced. 

d.  Unless  protected  in  some  way  by  a  shield  or  covering, 
a  station  in  the  floor  of  a  roadway  along  which  there  is  con- 
siderable haulage  is  liable  to  be  knocked  out.     This  is  espec- 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       75 


ially  true  when  the  motive  power  is  men  or  mules ;  with  rope  or 
locomotive  haulage  the  station  is  more  permanent. 

e.  The  character  of  the  roof  must  often  be  considered.     If 
the  roof  is  very  strong  there  is  probability  of  the  floor  rising ; 
if  the  roof  is  fragile  considerable   material   falls  and   must  be 
removed.     Stations  in  the  floor  of  an  entry  in  which  there  are 
frequent  falls  may  be  knocked  out  by  the  men  who  shovel  out 
the  rock. 

f.  The  station  to  be  permanent  should  consist  of  a  nail 
driven  into  a  wooden  plug  firmly  imbedded  in  the  floor  or  of  a 
rivet  firmly  imbedded  in  the  floor.     Nails  in  ties  or  in  cracks 
in  the  floor  can  hardly  be  classed  as  permanent  stations. 

g.  Stations  established  in  the  floor  are  liable  to  corrosion 
by  mine  water.     The  metal  may  be  entirely  dissolved  or  various 
materials  may  be  deposited  upon  it. 

h.  Stations  in  the  floor  when  near  working  places  will  be 
loosened  or  blown  out  by  shots. 

The  permanency  of  stations  established  in  the  roof  depends 
upon  (a)  the  marking,  (b)  the  character  of  roof,  (c)  the  char- 
acter of  station,  (d)  workmanship,  (e)  mine  water,  (f)  proximity 
to  workings,  (g)  character  of  floor. 

b.     When  the  roof  is  fragile,  the  station  may  drop  out. 

g.  When  the  floor  is  soft,  and  there  is  considerable  roof 
pressure,  material  is  forced  up  from  the  floor  and  the  roof  sinks 
thus  decreasing  the  elevation  of  the  station  or  dropping  it  out 
completely. 

The  permanency  of  a  station  established  in  timbers  depends 
upon  (a)  the  permanency  and  character  of  the  timber,  (b)  the 
settling  of  the  timber,  (c)  the  character  of  the  station,  (d)  mark- 
ing, (e)  the  proximity  to  working  places. 

a.  Stations  placed  in  poor  timbers  or  sets  which  may  be 
removed  cannot  be  considered  permanent,  in  fact  most  stations 
in  timber  are  temporary. 

b.  Timbers  frequently  settle  considerable,  especially  when 
the  bottom  is  soft  and  no  sill  is  used. 

e.  Timbers  set  near  working  places  may  be  knocked  down 
by  shots. 

Stations  may  be  established  in  timbers  which  must  be  locat- 
ed in  definite  positions  as  shaft  timbers. 

In  certain  systems  of  mining,  as  longwall  advancing,  it  is 
almost  impossible  to  keep  stations  in  the  roof,  which  fact  is  due 
to  the  caving  of  the  roof  as  the  work  advances.  As  longwall  is 
used  in  flat  seams,  horizontal  angles  alone  must  be  measured. 
The  sinking  of  timber  and  the  rising  of  the  floor  need  not  be 


16  A  STUDY  OF  MINE  SURVEYING  METHODS 

considered  when  no  horizontal  displacement  of  the  station  is 
noted.  Many  engineers  carry  stations  in  the  floor  under  such 
conditions. 

2.  Stations  should  be  so  located  that  (a)  the  fewest  num- 
ber, necessary  for  the  purpose,  be  used,  and  that  (b)  these  be 
at  the  most  available  and  useful  points. 

a.  Before  locating  stations  it  is  advisable  to  inspect  the 
workings  to  determine  the  most  advantageous  points  for  sta- 
tions. Short  sights  and  unnecessary  set-ups  can  often  be 
avoided  by  thus  planning  the  work.  Reference  stations  should 
be  established  at  convenient  points  in  back  entries  so  that  haul- 
age, etc.  may  not  interfere  with  the  work.  At  the  intersection  of 
important  roadways,  good  witness  stations  should  always  be 
established  because  points  at  intersections  are  often  knocked  out. 

Permanent  stations  should  be  located  where  there  is  little 
danger  of  their  being  disturbed,  not  always  at  the  most  conven- 
ient points. 

3.  Character  of  Station. 

a.  "The  simplest  top  station  is  a  shallow  conical  hole  made 
with  the  point  of  the  foresightman's  hatchet,  which  is  dug  into 
the  top  rock  and  rotated ;  it  is  called  by  some  a  jigger  station. 
Corps  using  these  entirely  have  a  jigger,  consisting  of  a  steel 
pointed  extension  rod  with  an  offset  holding  a  paint  brush.  The 
rod  is  long  enough  to  allow  the  point  to  be  driven  into  the  roof 
at  any  height,  and  its  rotation  marks  a  circle  with  the  brush, 
which  is  also  used  to  mark  the  number  beside  the  circle.     Cen- 
ters are  set  under  such  stations,  and  sights  are  given  by  another 
tool — also  called  a  jigger.     This  is  an  extension  rod,  beyond  the 
upper  end  of  which  projects  a  sheet  iron  shaped  like  an  isosceles 
triangle,  with  the  upper  and  smaller  angle  cut  off  so  as  to  form 
an  end  one  quarter  of  an  inch  broad,  and  in  this  end  is  cut  a  TJ 
shaped  groove.     The  sights  are  given  and  "centers"  set  by  put- 
ting a  plummet  chord  in  this  groove.     The  advantage  of  this 
method  lies  in  the  rapidity  with  which  the  centers  are  set.  and  the 
sights  given,  and  the  ease  with  which  the  highest  stations  are 
reached.     The   disadvantages   are   the   impossibility  of  making 
the  jigger  hole  perfectly  conical,  so  that  the  jigger  can  be   set 
in  the  same  place  on  two  successive  sights,  and  of  making  the 
plummet  chord  hang  in  exactly  the  same  place.  "* 

b.  Common  nails  may  be  driven  in  cracks  in  the  roof  or 
floor.    AVhen  the  nail  is  driven  in  the  roof  a  plumb  line  and  bob 
are  suspended.     When  the  nail  is  driven  in  the  floor  or  tie,  a 
pencil  or  rod  is  placed  vertically  over  the  nail  at  which  the  in- 
strument is  sighted. 

*f!oll.   Eng.  XIV,    10. 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       77 

c.  Spads,  spuds,  staples  or  screw  eyes  may  be  driven  into 
a  crack  in  the  roof  or  into  a  timber.  Spads  or  spuds  are  gen- 
erally made  by  hammering-  out  the  head  of  a  horseshoe  nail  and 
punching  a  hole  in  the  flattened  head  for  inserting  the  chord. 
Iron  or  copper  may  be  used  for  spads,  but  iron  is  generally  used 
because  it  cheaper.  It  is  not  advisable  to  make  a  station  in  a 
crack,  for  the  same  force  which  made  the  crack  may  cause  it 
to  open  further  and  the  station  will  then  drop  out.  Such  cracks 
are  generally  water  courses.  tfoT 

For  accurate  work  nails  should.be  used  because  the  plumb 
line  may  be  suspended  from  either  side  of  the  nail  and  in  short 
sights  the  error  due  to  the  width  of  a  nail  in  backsight  and 
foresight  will  soon  become  quite  appreciable. 

•  d.  A  spad  is  driven  into  a  wooden  plug  in  the  roof.  Holes 
from  i  YZ  "  to  6"  in  depth  and  of  such  diameter  that  the  spad  will 
not  split  the  plug  driven  into  the  hole  are  drilled  in  the  roof  at 
the  point  selected.  The  smaller  the  hole  the  quicker  the  work. 
Drilling  may  be  by  hammer  and  drill,  twist  drill  or  power  drill. 
When  the  roof  is  poor,  it  must  be  brushed  down  until  it  sounds 
firm  under  the  hammer.  When  the  roof  is  too  poor,  a  special 
type  of  station  may  be  put  in  or  a  timber  may  be  cut  in  to  support 
the  station  temporarily  and  a  permanent  point  may  be  establish- 
ed near  by. 

The  plug  is  of  wood,  of  slightly  larger  diameter  than  the 
hole,  tapered  at  one  end,  sawed  off  square  at  the  other,  slightly 
longer  than  the  depth  of  hole,  and  driven  up  flush  with  the  roof. 
When  wet  the  plug  expands  and  fills  the  hole  completely.  The 
wood  should  be  hard  enough  to  stand  driving  and  to  hold  the 
spad  and  should  not  split  when  the  spad  is  driven.  Good  plugs 
for  small  holes  can  be  made  from  broom  handles.  Plugs  and 
spads  should  always  be  made  on  the  surface.  The  spad  should 
be  driven  broadside  to  the  line  of  sight. 

e.  A  hole  3-32"  in  diameter  may  be  drilled  in  the  roof; 
a  cord  or  wire  placed  in  the  hole  can  be  held  firmly  by  a  small 
wooden  plug  driven  in  flush  with  the  roof.     A  lamp  or  bob  as 
desired  may  be  hung  from  the  cord  or  wire. 

f.  A  cylindrical  hole  may  be  drilled  in  the  roof.     A  clip 
made  by  bending  back  upon  itself  a  band  of  thin  steel  3-32" 
wide  having  a  hole  drilled  in  the  center  of  the  clip  may  be  placed 
in  the  hole.     The  clip  is  so  made  that  the  cord  passing  through 
the  hole  in  the  clip  always  hangs  from  the  center  of  the  hole  in 
the   roof.     After  the   observations   are   completed,   the   clip   is 
removed  from  the  hole  in  the  roof.     The  disadvantages  of  such 
a  station  are  important  ones.     The  roof  must  be  good  or  else 
uniform  holes  cannot  be  driven.     All  holes  should  be  of  small 
depth  and  circular  in  section.     The  clip  cannot  always  be  re- 


r8  A  STUDY  OF  MINE  SURVEYING  METHODS 

placed  in  the  holes  so  that  the  line  hangs  in  the  same  position  as 
at  first. 

g.  Stations  in  the  floor  may  be  made  by  placing  a  ^"  rivet 
in  a  hole  l/2"  diameter  and  2"  deep.  The  end  of  the  rivet  is 
split  and  a  wedge  of  wood  inserted  in  this  split  so  that  when 
the  rivet  is  driven  into  the  hole  it  wedges  fast.  A  mark  made 
on  the  rivet  head  gives  the  point  for  the  station. 

h.  When  the  roof  is  so  poor  that'  a  station  cannot  be 
established  in  it,  three  spads  are  driven  in  the  wall  near  the 
roof  for  the  support  of  the  following  device.*  In  the  center  of  a 
sheet  of  galvanized  iron,  cut  to  form  an  equilateral  triangle,  base 
i^4",  is  punched  a  small  hole  through  which  is  hung  a  plumb 
bob.  To  each  corner  of  the  triangle  is  attached  a  chain  by 
which  the  entire  device  may  be  hung  from  the  three  spads  in 
the  walls.  The  chains  are  of  equal  length  and  must  not  stretch. 
The  spads  should  be  so  located  that  the  plate  will  hang  horizon- 
tal and  the  plumb  bob  in  the  line  of  sight.  The  disadvantages 
of  such  a  station  lie  in  the  fact  that  three  points  must  be  pre- 
served instead  of  one.  The  bending  of  the  plate,  the  twisting 
of  the  chain  or  the  bending  of  the  hooks  by  which  the  chains  are 
hung  from  the  spads  will  prevent  the  hanging  of  the  bob  to 
duplicate  the  first  conditions.  In  low  entries  it  is  difficult  to 
manipulate  this  device  so  that  the  instrument  can  be  easily  set 
up  under  the  bob  so  suspended.  The  point  of  set-up  may  be 
marked  in  the  floor  and  the  instrument  set  up  over  this  point. 

4.     Marking  of  Stations.! 

a.  As  previously  stated  a  station  so  poorly  marked  that  its 
identity  cannot  be   determined  is  valueless  until   it  has  again 
been  properly  located.     Temporary  stations  need  not  be  mark- 
ed very  carefully  as  they  are  not  designed  to  be  of  future  benefit 
to  the  one  who  establishes  them. 

b.  In  addition  to  being  numbered  or  marked  to  distinguish 
from  other  stations  all  stations  should  be  so  witnessed  that  they 
can  be  readily  found. 

•Mines  and  Minerals  XIX,  247. 

f  A  number  of  large  and  well  managed  mines  do  not  mark  the  num- 
ber of  stations  underground.  All  stations  have  a  number  which  ap- 
pears in  the  note  book  and  on  the  maps.  There  may  be  cited  an  instance 
of  a  mine  operating  three  shafts  over  a  thousand  feet  in  depth.  There 
have  been  established  over  two  thousand  stations  not  one  of  which  can 
be  identified  by  any  one  unfamiliar  with  the  mine.  It  required  a  new 
surveyor  three  months  to  learn  the  mine  so  that  stations  could  be  found. 
Again  in  this  same  property  station  121  may  be  on  the  first  level  and 
station  122  on  the  eighth:  station  2001  on  the  ninth  and  station  2002  on 
the  third.  The  mine  officials  appear  to  be  well  satisfied  with  this  lack 
of  system. 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       JQ 


B.  Place.     Marks  may  be  made  (a)  on  the  station  itself, 
(b)  on  the  roof  or  walls,  and  (c)  on  the  timber. 

a.  It  is  rather  unwise  to  witness  the  station  on  itself;  if  the 
station  be  destroyed  there  is  no  mark ;  a  better  method  can 
easily  be  found. 

b.  In  coal  mines  the  roof  is  generally  smooth  and  the  walls 
rough.     In  metal  mines  very  often  one  or  both  walls  are  smooth 
and  the  roof  rough.     In  tunnels  generally  the  walls  and  roof  are 
all  rough.     When  walls  and  roof  are  equally  firm,  the  smooth 
surface  is  to  be  preferred. 

c.  Marking  on  timber  depends  on  the  permanency  of  tim- 
ber and  of  the  station.     It  is  difficult  to  paint  or  mark  on  rough 
timber ;  however,  dressed  timber  gives  a  good  surface  for  any 
kind  of  a  mark. 

C.  Kind  of  Marking. 

a.  Paint.     Some  geometrical  form  enclosing  the  station  or 
number  of  the  station  may  be  used.     When  the  station  is  in  the 
floor  a  vertical  line  is  drawn  on  one  of  the  walls  opposite  and  the 
station  number  enclosed  in  some  geometrical  form.     The  mark 
used  should  distinguish  the  station  from  those  of  other  surveys. 
The  color  of  the  paint  used  depends  upon  the  background.     For 
dark  walls  use  white  paint  (white  lead  mixed  with  linseed  oil) 
and  for  white  walls,  as  salt  and  gypsum,  use  dark  paint.     Suf- 
ficent  paint  for  the  day  should  be  carried  in  a  quart  tin  can.     A 
round  bristle  brush  about  one  inch  in  diameter  and  well  wound 
with  wire  in  order  to  make  it  stiff  enough  for  rough  work  is  used 
in  applying  the  paint  to  the  walls.     When  the  walls  are  very  wet, 
paint  is  not  to  be  recommended  as  it  comes  off  quickly. 

b.  Chalk.     When    the    instrument    man    marks    stations 
himself,   which   is   generally   when   he   desires   only   temporary 
stations,  chalk  may  be  used  on  dry  walls. 

c.  Nails   and  washers.     At  times   numbers  are   made   by 
driving  nails  into  timbers.     A  washer  is  used  to  denote  zero. 
Nails  may  be  driven  to  outline  figures  or  in  rows  composed  of 
the  same  number  of  nails  as  there  are  units  in  the  digit.     It  is 
rather  inconvenient  to  use  this  system  when  the  numbers  are 
large  or  where  there  is  little  timbering. 

d.  Tags.     These  are  generally  discs  of  brass,  zinc  or  lead, 
on  which  is   stamped  the  mark   for  the   station.     The  tag  is 
punched  and  through  the  hole  is  driven  the  spud  or  nail  of  the 
station.     It  may  be  painted  white  to  make  it  easily  seen.     Tags 
made  from  sheet  metal  upon  which  the  number  is  stamped  may 
be  hung  from  the  station.     When  the  station  drops  out  there 
is  no  clew  to  its  former  position. 

e.  Figures  chiseled  in  the  wall.     This  mark  is  very  per- 
manent in  good  rock,  and  is  the  best  for  wet  walls. 


20  A  STUD  Y  OF  MINE  S UR  VE YING  ME THODS 

All  marks  should  represent  good  workmanship ;  numbers 
and  letters  should  be  easily  legible.  In  some  way  they  should 
be  distinguishable  from  marks  of  other  surveys. 

D.  System  of  Marking.  Marks  to  be  of  value  must  be 
according  to  some  system.  The  importance  of  having  a  good 
system  can  be  readily  appreciated.  When  a  party  is  daily  es- 
tablishing stations  in  various  parts  of  a  large  mine,  unless  some 
method  is  used  in  marking  stations  it  will  be  necessary  to  have 
a  map  of  the  mine  at  hand  in  order  to  locate  a  given  station. 
Again  instead  of  the  station  identifying  itself  with  regard  to 
location,  the  map  must  again  be  used.  In  large  coal  mines 
openings  cannot  be  readily  identified  unless  stations  or  drifts 
are  intelligently  marked  according  to  some  system. 

a.  Frequently,  drifts  or  entries  are  named  and  the  stations 
on  the  drift  are  numbered  consecutively  towards  the  working 
face.     A  station  then  may  be  marked  Swede  Drift  9.     It  is  rath- 
er awkward  and  laborious  to  put  the  name  of  the  drift  at  each 
station. 

b.  Openings  may  be  lettered  and  stations  numbered  con- 
secutively as  in  (a).     A  station  then  would  be  marked  A  6,  or 
M  16,  R  21,  etc. 

c.  A  section  of  a  mine  may  be  given  a  letter  or  a  number ; 
as   all    ground   between    certain    boundaries   would    be   A   and 
stations  in  that  block  numbered  consecutively  as  A  i,  A  100, 
etc.  Levels  of  a  mine  may  be  lettered  or  all  stations  on  a  certain 
level  given  a  group  number,  as  all  stations  on  first  level  would 
be  100  to  199,  on  the  third  300  to  399,  etc. 

d.  When  drifts  or  openings  are  turned  off  at  regular  inter- 
vals these  may  be  numbered  consecutively  from  some  given 
point  and  with  regard  to  direction.     Along  a  main  entry  run- 
ning east  and  west,  side  entries  north  and  south  are  distiguished 
as  first  south  or  tenth  north.     Stations  are  numbered  consecu- 
tively on  the  main  entry  without  prefix  or  suffix.     On  the  side 
entries  we  may  number  ioN25  or  2833  meaning  station  25  on 
the  tenth  entry  to  the  north  and  station  33  on  the  second  entry 
to  the  south.     In  this  way  the  station  really  locates  itself.     In- 
stead of  numbering  the  stations  consecutively,  distance  from  a 
given  point  may  be  used.     Suppose  a  station  is  307.46  feet  from 
the  main  entry  on  the  fifth  south,  the  mark  should  be  583+07.46. 

e.  The  system  of  numbering  stations  consecutively  as  they 
are  put  in  is  very  poor  practice.     By  this  method  station  356 
may  be  in  one  part  of  a  mine  and  357  in  another  part  possible  a 
mile  distant. 

Various  modifications  of  these  systems  may  be  adapted  to 
circumstances. 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       21 

5.  Point  of  Sight.  In  surveying  underground  artificial 
light  is,  of  course,  necessary  both  at  the  instrument  and  the  point 
sighted.  Various  devices  have  been  used  to  illuminate  the 
point  sighted. 

a.  Common  practice  is  to  use  a  light  as  the  point  of  sight. 
The  point  of  light  used  depends  largely  upon  the  character  of 
the  mine  and  what  kind  of  light  the  miners  use.     In  metallifer- 
ous mines  the  tallow  candle  is  used,  in  coal  mines  an  open  lamp 
burning  lard  oil  or  the  safety  lamp.     The  acetylene  and  electric 
lamps  are  sometimes  used  by  mining  engineers.     When  locating 
points  in  rooms  or  stopes  or  at  the  breast  of  drifts,  the  light  is 
often  sighted  at  instead  of  an  established  point. 

b.  A  rod,  nail  or  pencil  properly  illuminated  may  be  used 
for  rough  sights.     When  the  side  telescope  is  used,  the  double 
or  lop-sided  target  may  be  used  instead  of  the  ordinary  rod  or 
plumb  bob.     The  double  target  is  so  constructed  that  the  point 
sighted  at  on  the  target  is  not  directly  under  the  station  but  off 
to  one  side  a  distance  equal  to  the  distance  from  the  axis  of  the 
side  telescope  to  the  station  under  which  the  instrument  is  set, 
or   equal  -to  the  distance   between  telescopes.     When   such   a 
target  is  used  no  correction  need  be  made  for  the  side  telescope. 

c.  A  plumb  line  suspended  from  the  station  is  the  common 
point  of  sight.     The  vertical  wire  of  the  instrument  is  set  upon 
the  line  or  upon  the  point  of  the  bob.     In  order  to  facilitate  the 
measurement  of  distance  and  to  have  uniformity  in  the  work,  it 
is  quite  common  to  loop  the  line  about  a  nail  or  a  match  so  that 
when  the  line  is  stretched  taut  by  the  weight  of  the  bob  the  nail 
or  match  will  hang  horizontal,  thus  giving  a  good  point  upon 
which  to  set  the  horizontal  wire.     The  vertical  angle  and  meas- 
urements to  the  instrument  and  to  the  roof  and  floor  are  taken 
with  regard  to  this  point.     To  illuminate  the  line  or  bob  suffi- 
ciently a  sheet  of  oiled  paper  or  tracing  cloth  should  be  placed 
in  the  line  of  sight  back  of  the  plumb  line  and  back  of  the  paper 
the  light. 

d.  In  (a)  it  was  suggested  that  the  sight  be  taken  at  the 
naked  light,  Mr.  Coxe  adapted  the  plummet  lamp  which  consists 
of-a  heavy  lamp  suspended  from  two  or  three  chains  so  that  the 
whole  can  be  easily  hung  from  an  established  point  in  the  roof. 
The  lamp  always  hangs  at  the  same  distance  below  its  point  of 
support.     When  the  transitman  is  ready  to  sight,  the  lamp  is 
hung  and  lighted  and  the  flame  bisected  by  the  vertical  wire,  the 
horizontal  wire  being  set  upon  the  proper  point  of  the  lamp. 

e.  In  the  three  tripod  system  the  point  of  sight  is  again  a 
lamp  but  instead  of  being  suspended  from  the  roof  it  is  sup- 
ported on  a  tripod  similar  in  every  way  to  the  one  on  which 
the  transit  is  set  up. 


22  A  STUDY  OF  MINE  SURVEYING  METHODS 

f.  Instead   of  having  an  illuminated  background   against 
which  the  point  of  sight  wrill  show  plainly,  the  background  may 
be  darkened  and  the  line  of  sight  illuminated.     This  is  accom- 
plished by  cutting  a  horizontal  and  a  vertical  slit  in  a  sheet  of 
metal  and  after  the  sheet  has  been  placed  so  that  the  slit  will 
be  in  the  proper  line,  the  lamp  placed  behind  the  slit  illuminates 
the  slit. 

Vertical  sheets  of  metal  in  the  same  plane  and  so  mounted 
that  they  can  be  easily  shifted  have  been  mounted  on  a  plat- 
form and  placed  behind  wires  used  in  shaft  plumbing.     By  this 
arrangement  the  sheets  may  be  shifted  so  that  a  vertical  line  of 
sight  may  be  developed  directly  back  of  the  wire  sighted. 

g.  Various   patent   devices   for   sighting   in   underground 
work  have  been  put  upon  the  market.     One  of  the  best  of  these 
consists  of  a  strip  of  sheet  metal  about  2"  wide  and  12"  long. 
At  either  end  are  cut  holes  so  that  the  strip  may  be  suspended 
from  the  station  by  a  cord  and  from  the  lower  end  of  the  strip 
the  plumb  bob  is  hung.     A  number  of  holes  are  drilled  in  the 
strip,  the  centers  being  on  the  line  between  the  upper  and  lower 
cords.     Half  wray  between  the  ends  of  the  strip,  the  hole  drilled 
is  about  yz"  diameter,  from  the  center  towards  each  end  the 
holes  diminish  in  diameter  and  are  far  enough  apart  so  that  there 
remains  between  adjacent  holes  about  */6"  of  metal.     When  a 

-.  light  is  placed  behind  the  strip,  the  strip  being  at  rest,  a  vertical 
line  of  sight  appears  to  the  instrument  man.  He  can  also  sight 
at  the  plummet  as  it  revolves,  bisecting  the  ellipse  of  light  in 
the  center.  The  different  sizes  of  holes  will  suit  long  or  short 
distances  by  allowing  more  or  less  light  to  pass  through. 

BASE  LINE. 

T.  A  base  or  reference  line  should  always  be  estimated  or 
selected  before  any  attempt  is  made  to  carry  the  meredian  un- 
derground. It  is  always  advisable  to  establish  the  meredian 
before  doing  any  underground  surveying.  If  this  be  not  done 
it  will  always  be  necessary  to  correct  bearings  or  later  on  to 
change  the  entire  set  of  field  notes.  The  importance  of  having 
such  line  is  very  obvious  especially  when  several  openings  are 
made  on  one  property  and  it  is  necessary  to  survey  for  con- 
nections. 

2.  Such  a  base  line  should  be  marked  by  permanent  sta- 
tions that  will  be  accessible  at  all  times  if  possible.  In  districts 
in  which  the  ground  is  covered  deep  with  snow  during  manv 
months  in  the  year,  points  must  be  established  where  they  will 
not  be  covered  very  deep  or  where  they  can  be  found  easily. 
These  points  should  be  convenient  to  shafts  or  openings  so  that 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       23 


sights  to  the  same  line  can  be  taken  from  any  opening.  When 
such  arrangement  cannot  be  made  a  trangulation  system  should 
be  laid  out. 

3.  All  uderground  surveys  of  adjacent  properties  should 
be  referred  to  the  same  base  and  the  same  datum.  Unless  this 
is  done  at  once  corrections  will  have  to  be  made  when  connec- 
tions between  adjacent  workings  are  calculated.  Notes  should 
be  taken  in  the  same  way  and  azimuth  measured  always  from 
the  south  or  always  from  the  north. 

After  the  base  line  or  reference  system  has  been  established, 
some  point  or  points  should  be  located  in  or  about  the  mouth 
of  the  tunnel  or  collar  of  the  shaft.  About  a  tunnel  this  is 
sometimes  difficult  because  the  ground  adjacent  will  be  graded, 
or  covered  with  waste  rock,  or  the  track  arrangement  may  not  be 
permanent.  Owing  to  the  hoisting  rope,  sheave  and  dumps  it 
is  almost  impossible  to  locate  a  permanent  point  over  a  shaft. 
This  is  especially  true  of  vertical  shafts.  Timbers  or  pipes  being 
taken  into  the  mine  often  knock  out  points.  The  engineer 
should  at  once  look  over  the  ground  and  find  some  point  adja- 
cent to  the  shaft  which  will  not  be  disturbed. 

CARRYING  THE  LEVEL  AND  MERIDIAN  INTO  THE 
MINE. 

In  order  that  underground  points  may  be  located  with 
regard  to  points  on  the  surface  it  is  essential  that  by  some 
means  the  meridian  be  carried  into  the  mine.  In  other  word's 
a  survey  must  be  made  from  the  surface  through  the  openings 
to  points  in  the  mine.  Such  an  opening  may  include  measur- 
ing the  depth  of  the  shaft,  plumbing  the  shaft  or  carrying  the 
line  underground  by  direct  sighting  with  the  transit. 

Levels.  The  depth  of  a  shaft  or  opening  may  be  deter- 
mined. 

(a)  By  the  aneroid  barometer  when  only  a  rough  figure 
is  desired.  Read  the  barometer  at  the  surface,  also  noting  the 
temperature ;  then  go  underground  to  the  bottom  and  read  the 
barometer,  noting  temperature.  The  barometer  reading  should 
be  taken  several  times ;  after  the  barometer  reading  is  constant 
return  at  once  to  the  surface  and  again  take  several  readings  at 
the  surface.  Corrections  for  difference  in  temperature  between 
the  mine  openings  and  the  surface  should  be  made.  The  mean 
of  the  difference  between  reading  taken  at  the  surface  and  un- 
derground is  the  depth  of  opening. 

b.  The  depth  of  a  vertical  or  inclined  shaft  of  uniform  dip 
may  be  determined  by  measuring  the  length  of  the  hoisting 
rope  used  in  reaching  the  bottom  of  the  shaft.  In  order  to  do 


24  A  STUDY  OF  MINE  SURVEYING  METHODS 

this  the  number  of  revolutions  of  the  head  sheave  during  the 
hoist  should  be  noted.  The  circumference  of  the  sheave  being 
known  the  amount  of  rope  wound  can  be  easily  calculated,  or 
two  marks  can  be  made  on  the  rope,  one  opposite  a  fixed  point 
when  the  cage  or  skip  is  at  the  bottom,  another  after  the  cage 
or  skip  has  been  brought  to  surface,  opposite  the  same  point. 
The  rope  between  these  marks  represents  the  depth  of  the  shaft. 
When  the  winding  drum  is  cylindrical  the  rope  round  and  not 
winding  on  itself,  determine  the  circumference  of  the  drum,  the 
number  of  coils  or  rope,  then  the  amount  of  rope  between  the 
two  marks  can  be  roughly  calculated.  When  the  rope  winds  on 
itself  during  part  of  the  hoist,  correction  must  be  made  for  the 
increased  diameter  due  to  the  rope.  When  the  drum  is  conical, 
measure  the  diameters  at  each  end  of  the  surface  on  which  the 
rope  is  wound,  determine  the  number  of  coils  of  rope  wound 
during  hoisting  the  length  of  rope  can  then  be  roughly  esti- 
mated. When  the  spiral  drum  or  differential  drum  is  used  it  is 
necessary  to  know  the  equation  of  the  curve  of  the  drum,  the 
number  of  grooves  per  foot  of  face  of  drum  and  the  number  of 
coils  of  rope  wound.  When  flat  rope  is  used,  the  thickness  of 
rope,  diameter  of  reel  or  reel  and  rope  when  the  skip  is  at  the 
bottom,  diameter  of  reel  and  rope  when  the  skip  is  at  the  top 
should  be  determined.  Then  either  algebra  or  calculus  may 
be  employed  to  determine  the  length  of  rope. 

c.  "A  steel  wire  is  unwound  from  a  reel  on  the  surface  and 
passed  over  a  pulley,  dropping  down  into  the  shaft  and  held 
taut  by  a  weight  at  the  end.  There  is  a  horizontal  scale  over 
which  the  wire  passes.  The  measurement  is  begun  by  lowering 
the  weight  a  short  distance  and  placing  a  mark  on  the  wire  at  a 
point  which  is  at  the  height  of  the  point  from  which  the  depth 
is  to  be  measured.  At  the  same  time  a  slight  mark  is  made  in 
the  wire  opposite  the  zero  point  of  the  scale.  The  wire  is  then 
unwound  until  this  mark  moves  to  a  point  of  graduation  when 
this  distance  of  travel  is  measured  on  the  scale  and  recorded. 
Then  another  mark  is  put  on  the  wire  at  the  zero  point  and 
another  part  is  measured,  and  thus  the  measurement  continues 
by  segments  until  the  weight  has  nearly  reached  the  bottom 
of  the  shaft.  Then  a  level  line  from  an  instrument  (under- 
ground) will  determine  a  point  on  the  side  of  the  shaft  at  the 
height  of  the  first  mark  made  on  the  wire.  Then 'the  last  portion 
of  the  wire  that  was  unwound  is  measured  on  the  scale  and  the 
total  depth  is  equal  to  the  sum  of  all  the  parts  measured  on  the 
scale.  The  depth  may  also  be  measured  when  the  reel  is  wound 
up  and  the  two  results  compared."* 


*Nugent's  Plane  Surveying,  p.  356. 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       25 

d.  The  depth  of  shaft  may  be  measured  directly. by  means 
of  a  tape.     A  nail  is  driven  in  the  collar  of  the  shaft,  the  eleva- 
tion of  which  nail  is  known  and  from  which  nail  is  suspended  the 
tape.     Then  a  man  with  the  reel  on  top  of  the  cage,  unwinds 
the  tape  as  the  cage  is  lowered  till  the  end  of  the  tape  is  reached. 
Then  he  drives  another  nail,  ascends  to  surface,  unhooks  the 
tape  and  proceeds  to  the  last  nail  set ;  again  from  that  point  he 
proceeds  as  before  until  the  reaches  the  bottom. 

e.  An  instrument  equipped  with  top  or  side  telescope  may 
be  set  up  over  the  shaft  and  the  heighth  of  instrument  being 
known,  the  telescope  is  depressed  until  the  vertical  circle  shows 
that  the  telescope  is  vertical.     A  point  on  the  bottom  is  then 
established  directly  under  the  instrument,  but  distant  from  the 
center   the    distance    between    telescopes.     In    the   line    of   the 
telescope  another  point  as  far  as  possible  from  the  first  point 
is  established  on  the  bottom  and  the  vertical  angle  to  this  is 
read.     Both  points  on  the  bottom  should  be  at  the  same  eleva- 
tion.    The  distance  between  these  points  can  be  measured.     We 
have  then  a  right  triangle,  which  can  easily  be  solved  for  the 
long  side — the  depth  of  shaft.     In  order  to  check  this,  several 
lines  may  be  established  in  the  same  way  and  the  depth  calcu- 
lated. 

Knowing  the  elevation  of  the  collar  and  the  depth  of  shaft 
the  elevation  of  the  bottom  is  determined  and  proper  bench 
marks  are  established. 

f.  To  determine  the  elevation  of  the  bottom  of  an  inclined 
or  crooked  shaft,  it  is  generally  advisable  to  run  a  traverse  with 
the  top  or  side  telescope  from  a  known  bench   mark  on  the 
surface.    The  depth  of  shaft  can  then  be  readily  computed. 

To  carry  the  meredian  down  an  inclined  shaft  or  slope  it 
becomes  necessary  to  observe  (a)  the  horizontal  angle  or  azimuth 
(b)  the  vertical  angle,  (c)  the  distance,  (d)  the  height  of  instru- 
ment and  (d)  the  height  of  the  point  sighted.  For  highly  in- 
clined openings  it  becomes  necessary  to  use  an  auxiliary  tele- 
scope because  of  the  interference  of  the  main  telescope  with  the 
plate.  Eccentric  bearings  may  be  used  but  most  engineers 
prefer  the  auxiliary  telescope.  Such  telescopes  must  be  ad- 
justed so  that  by  easy  calculations  the  proper  line  may  be  found. 
The  top  telescope  is  mounted  so  that  when  the  main  telescope 
is  horizontal,  it  is  also  horizontal  and  with  the  vertical  wire  in 
the  same  plane  with  the  vertical  wire  of  the  main  telescope.  The 
horizontal  wire  of  the  top  telescope  should  be  so  adjusted  when 
sighted  say  at  a  rod  two  hundred  feet  from  the  instrument,  the 
main  telescope  being  horizontal,  the  difference  in  readings  on 
the  rod  corresponds  to  the  vertical  distance  between  telescopes. 


26  A  STUDY  OF  MtNE  SURVEYING  METHODS 

When  the  side  telescope  is  used,  horizontal  wires  of  the 
main  and  of  the  auxiliary  telescope  should  be  in  the  same  plane 
and  when  the  instrument  is  sighted  at  a  vertical  plane  surface 
about  two  hundred  feet  distance  instrument,  the  distance  be- 
tween points  in  the  line  of  sight  of  the  main  telescope  and  the 
side  telescope  should  correspond  to  the  horizontal  distance 
between  telescopes. 

Distances  may  be  measured  from  the  instrument  or  the 
station  established  to  either  the  point  of  sight  or  the  next 
station.  Most  engineers  prefer  to  measure  from  the  axis  of 
the  main  telescope  to  the  point  sighted.  It  becomes  necessary 
then  to  make  various  readings.  Notes  are  often  kept  in  the 
following  form: 


Az.  |  Mag.  Bear.  |  V.  A.     M.  D.  |  H.  I.  |  H.  Ft. 


An  accompanying  figure  shows  for  the  top  telescope  the 
various  angles  and  distances,  except  azimuth,  which  should  be 
noted.  The  distance  between  telescopes  should  be  a  constant. 
Numerous  Greek  letters  have  been  eliminated,  in  order  that  the 
difficulties,  which  are  numerous  enough  for  the  average  student, 
be  not  multiplied.  The  object  has  been  to  make  the  student 
think  in  terms  of  actual  observations  rather  than  in  abstract  let- 
ters. 

The  student  should  note  that  in  the  use  of  the  side  tele- 
scope when  the  vertical  angle  is  90°,  no  point  above  or  below 
the  instrument  can  be  sighted  if  it  lies  within  the  right  cylinder 
generated  by  turning  the  instrument  on  the  horizontal  plate. 
This  cylinder  will  have  a  radius  equal  to  the  distance  between 
telescopes.  Under  the  same  conditions  a  top  telescope  will 
also  generate  a  similar  right  cylinder  but  this  'cylinder  does  not 
mark  the  limit  of  sight  of  the  top  telescope.  Points  directly 
under  the  center  of  the  instrument  are  visible  up  to  a  certain 
limit  which  is  determined  by  the  ratio  between  the  distance 
between  the  telescopes,  the  diameter  of  horizontal  plates  and 
the  height  of  standards.  Assume  a  point  directly  under  the 
center  of  the  instrument ;  this  is  not  visible  through  the  side 
telescope  but  may  be  through  the  top  telescope  if  the  vertical 
angle  is  not  much  over  90°.  An  infinite  number  of  horizontal 
angles  but  only  one  vertical  angle  may  be  read  for  such  a  point 
as  it  is  the  apex  of  a  right  cone,  the  center  of  whose  base  is  the 
center  of  the  instrument.  Any  point  above  the  plane  of  the 
plate  of  an  instrument  is  visible  through  the  top  telescope. 

Plumb  lines  and  wires  may  be  used  to  carry  a  line  from  the 
surface  underground  through  an  inclined  shaft.  When  the 
shaft  is  sunk  on  several  dips  the  problem  requires  considerable 
care.  When  the  line  of  the  shaft  is  known  approximately,  a 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       27 


wire  is  stretched  from  the  surface  to  a  point  well  down  the  shaft. 
The  bearing  of  the  wire  is  established  by  two  bobs  hung  so  that 
the  cords  just  touch  the  wire  on  the  same  side.  Two  bobs  are 
hung  in  the  same  manner  underground.  When  the  shaft  is  on  a 
uniform  dip,  the  wire  may  be  stretched  taut ;  when  the  dip  dimin- 
ishes the  wire  may  be  hung  to  clear  the  sag  in  the  shaft.  Plumb 
bobs  are  hung  on  the  line  in  the  same.  way.  Having  established 
two  points  underground,  the  wire  may  be  taken  down  the  shaft 
and  hung  in  the  line  of  the  two  stations  and  two  more  establish- 
ed further  down.  Great  care  must  be  taken  that  bobs  are  always 
hung  on  the  same  side  of  the  wire  and  that  all  points  are  proper- 
ly aligned. 

When  two  or  more  inclined  shafts  are  connected  under- 
ground surveys  should  be  made  if  possible  connecting  survey 
points  established  at  the  various  levels.  When  there  is  but  one 
opening,  in  carrying  the  meredian  into  the  mine,  great  care 
should  characterize  the  work.  All  surveying  should  be  care- 
fully done  but  greater  precision  is  essential  to  shaft  work,  espe- 
cially when  but  one  line  can  be  run,  because  all  subsequent 
work  depends  upon  the  accuracy  in  location  of  the  shaft  stations. 

Vertical  shafts.  When  there  is  but  one  vertical  shaft  there 
is  nothing  to  check  the  work. 

a.  When  the  shaft  is  not  very  deep  or  wet  the  transit 
equipped  with  Auxiliary  telescope,  may  be  used.  The  instrument 
is  set  up  at  the  collar  of  the  shaft,  back  sight  is  taken  on  a 
known  point  and  two  points  in  the  line  of  the  instrument  are 
established  at  the  bottom  of  the  shaft,  as  far  apart  as  possible 
and  both  visible  from  the  tarnsit.    The  azimuth  of  the  line  un- 
derground can  be  readily  calculated  when  all  the  distances  are 
measured.     This  method  is  used  in  some  of  the  deep  level  shafts 
of  the  Rand. 

b.  For  deep  and  wet  shafts  it  is  advisable  to  hang  wires 
from  the  slurface.    When  there  are  two  shafts,  but  one  wire  is 
necessary  to  each  shaft.     Underground  and  surfaces  traverses 
are  run  to  connect  the  wires  which  should  be  suspended  at  the 
same  time.     The  azimuth  of  the  plane  through  the  two  wires 
can  thus  be  determined.     When  there  is  but  one  opening  two 
wires  should  be  hung  from  the  surface  in  a  line  the  azimuth  of 
which  is  known.    Copper  or  steel  wire  may  be  used ;  copper  is 
generally  preferred  for  shallow  shafts.     Hang  an  8  pound  bob 
from  a  No.  20  copper  wire.     These  wires  should  be  as  far  apart 
as  possible,  should  hang  free,  should  not  interfere  with  hoist- 
ing and  should  be  so  located  that  the  transit  can  be  set  up  in 
line  with  them  underground.    The  wires  should  be  lowered  from 
the  surface,  a  light  bob  being  attached  to  the  wire  in  order  to 
keep  it  from  catching  on  timbers,  etc.    When  the  wire  extends 


2$  A  STUDY  OF  MINE  SURVEYING  METHODS 

to  the  bottom,  it  should  be  drawn  up  so  that  it  will  clear  the 
bottom  even  though  it  does  stretch  a  little.  It  is  generally  ad- 
visable to  lower  the  wires  one  at  a  time  and  to  draw  the  first 
wire  taut  in  the  same  corner  from  which  it  is  suspended  at  the 
surface  in  order  that  the  second  wire  may  not  be.  entangled 
withjtr  In  plumbing  the  Tamarack  shafts  4,250  feet  deep,  No.  24 
piano  wire  was  used.  This  was  lowered  by  means  of  a  small 
two  cylinder  hoist  operated  by  compressed  air.  The  lowering 
weights  consisted  of  two  balloons  or  frames,  ten  feet  long  and 
two  and  a  half  feet  in  diameter  at  center  tapering  to  a  point  at 
each  end.  These  were  made  of  slats  and  weighed  twenty  pounds. 
A  lantern  was  hung  in  the  center  of  each  so  that  its  progress 
down  the  shaft  might  be  observed.  It  took  half  an  hour  to- reach 
the  bottom.  Eight  pound  bobs  were  then  attached  and  the  lines 
brought  so  far  from  the  center  of  the  shaft  as  possible.  When 
the  wires  were  in  place  fifty  pound  cast  iron  bobs  were  substi- 
tuted for  the  eight  pound  ones,  when  the  wires  immediately 
stretched  fifteen  feet.  They  were  then  cut  to  the  proper  length 
and  the  bobs  immersed  in  pails  of  engine  oil ;  this  resulted  in 
the  shortening  of  the  wires  twenty-five  inches  due  to  the  buoyant 
effect  of  the  oil  on  the  weights.  One  of  the  members  of  the 
party  should  inspect  the  wires  to  see  that  they  are  hanging  free. 
It  is  always  advisable  to  see  that  no  ventilating  currents  cause  a 
deflection  of  the  wires.  Water,  oil  or  molasses  may  be  placed  in 
the  vessel  in  which  the  bobs  hang. 

The  distance  between  the  wires  and  the  azimuth  of  the  line 
through  them  should  be  carefully  determined.  Then  set  up  the 
tripod  underground  as  nearly  as  possible  in  line  with  the  wires 
and  by  means  of  the  shifting  head  place  the  transit  in  the  line 
of  the  wires.  The  known  line  on  the  surface  is  thus  projected 
underground.  Establish  a  point  over  the  instrument  and  another 
point  in  the  line  of, the  wires,  at  a  good  distance.  Measure  the 
distance  between  the  wires  and  distances  from  the  instrument  to 
the  wires  and  to  the  established  point. 

When  the  compartment  of  the  shaft  is.  small  it  is  advisable 
to  hang  more  than  two  wires.  When  four  are  hung,  their  posi- 
tion should  be  determined  on  the  surface  with  regard  to  some 
known  line.  Two  points  should  be  established  underground, 
from  each  of  which  the  other  can  be  seen  and  also  all  the  wires. 
Set  up  at  both  points,  read  the  angles  to  the  wires  and  the 
other  point  and  measure  the  distances.  Calculate  the  azimuth 
of  the  line  through  the  two  established  points. 

Plumbing  shafts  requires  considerable  time  and  often  in 
order  to  make  the  interference  with  mining  operations  as  brief 
as  possible,  engineers  do  not  wait  for  the  bobs  to  come  to  rest 
but  bisect  the  arc  of  vibration.  This  may  be  done  by  tracing  on 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       29 

a  sheet  of  paper  the  elliptical  path  of  the  bob  as  it  swings.  The 
center  of  the  ellipse  can  then  be  taken  as  the  point  of  sight,  or 
the  extereme  points  in  the  arc  of  vibration  may  be  marked  on  a 
sheet  of  paper  placed  on  a  heavy  board,  the  line  joining  these 
points  is  bisected  and  the  middle  point  taken  for  the  sight.  Var- 
ious other  methods  may  be  used  in  carrying  the  meridian  down 
the  shaft.  The  co-called  T  square  method*  has  been  successfully 
use  on  the  Comstock  lode. 

UNDERGROUND  TRAVERSING. 

By  a  traverse  is  meant  a  series  of  consecutive  courses 
whose  lengths  and  bearings,  or  azimuths,  are  determined.  A 
traverse  is  then  a  system  of  connected  lines,  the  second  starting 
from  the  first,  the  third  from  the  end  of  the  second  and  so  on. 
A  transit  is  said  to  be  "oriented"  when  it  is  set  up  with  the  hor- 
izontal circle  in  such  a  position  that  if  the  vernier  is  made  to 
read  zero  the  line  of  sight  will  be  parallel  to  the  meridan.  When 
carrying  on  an  extended  survey  it  it  most  convenient  to  carry 
angles  by  the  continuous  azimuth.  Many  engineers  prefer  to 
read  angles  between  lines  of  the  traverse,  always  turning  either 
to  the  right  or  left.  These  reading  can  be  easily  checked  by 
repeating  the  angles.  Having  established  the  azimuth  of  a  line 
underground,  the  meridian  can  be  carried  to  any  part  of  the 
excavation  and  by  accurate  measurements  the  position  of  any 
point  determined  with  regard  to  any  other,  either  underground 
or  on  the  surface.  For  accurate  work  vertical  angles  should 
always  be  read  and  measurements  taken  from  the  axis  of  the 
instrument  to  the  point  of  sight,  the  height  of  instrument, 
height  of  point  and  measurements  to  show  the  distances  of  the 
stations  from  the  walls  and  distances  to  any  irregularities  not 
sufficient  to  deflect  the  traverse.  When  a  line  is  being  extended 
in  order  to  determine  the  proper  direction  to  drive  an  opening 
to  connect  with  another,  very  few  measurements  save  those  es- 
sential to  the  traverse  are  taken.  In  mapping  a  mine  all  exca- 
tions  must  be  noted  and  measured  so  that  they  may  appear 
properly  on  the  map. 

The  duties  of  the  various  members  of  the  party  have  already 
been  noted. 

The  cross  wires  may  be  illuminated  by  (a)  a  reflector,  —  an 
elliptical  silvered  plate  inclined  at  an  an  angle  of  45°  with  the 
ring  which  carries  it,  and  by  means  of  which  it  is  fitted  to  the 
object  end  of  the  telescope ;  (b)  by  a  half  cylinder  of  white 
cardboard  fastened  to  the  telescope  with  an  elastic  band,  and 
light  reflected  from  it  to  the  cross  hairs ;  (c)  by  use  of  a  sheet 
*Mines  and  Minerals  XIX,  242. 


jo  A  STUDY  OF  MINE  SURVEYING  METHODS 

of  white  paper  rolled  into  a  cone  truncated,  placed  with  the 
large  end  over  the  object  glass,  a  circular  hole  cut  in  the  middle 
of  the  cone  and  a  candle  held  opposite  the  hole. 

The  transitman  sets  up  under  a  known  point ;  the  back- 
sightman  illuminates  the  point  under  a  known  station.  The 
transitman  clamps  the  vernier  on  the  known  azimuth  of  the 
line  determined  by  his  instrument  and  the  backsight ;  plunges  the 
telescope  and  sets  on  the  backsight  and  clamps  the  lower  plate. 
(Some  engineers  prefer  to  set  the  vrnier  at  180°  less  than  the 
reading  for  the  last  foresight  on  the  main  traverse  and  back- 
sight without  plunging  the  telescope.)  Then  he  plunges,  sights 
on  the  new  point  established  in  the  meantime  by  the  foresight, 
clamps  the  lower  plate  and  reads  the  azimuth  of  the  line  through 
the  point  of  transit  and  the  new  point.  For  accurate  work  he 
should  repeat  the  angle.  Then  the  instrument  man  reads  the 
vertical  angle  and  measures  the  height  of  instrument,  while  the 
foresightman  measures  the  height  of  point  and  together  with 
the  instrument  man  or  backsightman  measures  from  the  axis 
of  the  instrument  to  the  point  sighted.  The  distance  is  known 
as  the  "measured  distance"  or  "slope  distance." 

The  three  tripod  method  of  traversing  has  been  used  some- 
what but  is  not  considered  very  practical  in  that  it  requires 
three  tripods  and  requires  that  the  party  shall  contain  a  man, 
in  addition  to  the  transitman,  who  can  set  up  an  instrument  so 
that  it  can  be  used  for  often  a  considerable  lenght  of  time.  It 
is  totally  impracticable  for  traversing  along  roadways  in  which 
traffic  frequently  interrupts  the  surveying  party.  The  equip- 
ment for  this  work  comprises  an  ordinary  transit,  three  exten- 
sion tipods  so  constructed  that  the  transit  can  be  undamped 
and  removed,  leaving  the  leveling  screws  on  the  tripod,  and  two 
plummet  lamps  which  may  be  set  and  clamped  upon  the  tripod 
when  the  transit  is  removed.  These  lamps  carry  spirit  levels  so 
that  they  can  be  leveled.  The  steps  in  the  operation  are  these: 
Suppose  the  transit  to  be  set  up  under  a  known  point ;  a  back- 
sight is  given  by  plumb  bob ;  the  elevation  of  the  station  being 
known ;  the  height  of  instrument  is  determined.  The  foresight- 
man sets  .up  under  the  next  point,  centering  and  leveling  as  with 
the  transit ;  having  properly  set  up,  the  tripod  being  set  very 
firmly,  the  lamp  is  lighted  and  the  foresight  given.  When  the 
point  of  sight  on  the  light  is  the  same  height  above  the  plate 
as  the  telescope,  the  height  of  instrument  need  be  taken  only  by 
the  foresightman.  Having  measured  distances  and  read  the 
angles  the  transitman  takes  the  transit  off  the  tripods,  takes  the 
third  tripod  from  the  backsightman,  and  carries  tripod  and  tran- 
sit to  foresight.  The  foresightman  removes  his  plummet  from 
the  tripod  in  place,  places  it  upon  the  tripod  brought  up  by  the 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING      31 

transitman  and  goes  ahead  to  establish  the  next  station.  The 
transitman  simply  sets  his  instrument  upon  the  plate  already 
centered  and  leveled  and  is  ready  to  backsight.  The  transitman 
does  not  have  to  bother  setting  up,  but  it  generally  pays  to  have 
him  check  the  set  up  before  making  any  sights  ;  so  the  real 
purpose  of  the  three  tripods  is  not  gained. 

In  working  with  the  top  and  the  side  telescopes,  or  with 
angles  above  60°  trouble  is  apt  to  occur  from  the  increased  and 
magnified  effects  of  personal  and  instrumental  errors.  These 
errors  may  be  divided  into  classes  (a)  variable  errors,  and  (b) 
constant  errors. 

a.  Variable    errors.      I.      Centering   the    instrument.      A 
sight  of  50  feet  with  a  vertical  angle  of  85°  gives  a  horizontal 
distance  of  4.35  feet.    In  a  circle  of  that  radius  an  arc  of  .0013 
feet  subtends  an  angle  of  one  minute,  which  means  that  a  dis- 
placement of  .0013  feet  in  position  of  the  instrument  bob  would 
give  an  error  of  that  amount 

II.  Leveling  the  instrument.  If  the  plate  is  one  minute 
from  the  horizontal  an  error  of  eleven  minutes  in  azimuth  may 
occur  with  the  vertical  angle  of  85° 

b.  Constant  errors  may  be  due  to  inclination  of  the  stand- 
ards, errors  in  collimation  and  the  eccentricity  of  the  telescope 
axis. 

The  work  should  be  carried  on  and  the  notes  so  kept  that 
any  other  surveyor  can  come  in  and  take  up  the  work  at  any 

"c 


SURVEYING   THE   MINE. 

-  The  survey  of  the  mine  as  a  whole  has  for  its  object  the 
production  of  a  map  to  show  essentially  the  underground  work- 
ings For  flat  veins,  seams  or  beds,  a  horizontal  plan  is  generally 
the  only  map  made.  However  for  highly  inclined  veins  in  order 
that  all  features  of  the  work  may  be  readily  observed  it  is  not 
uncommon  to  make  three  or  four  sheets,  —  a  horizontal  projec- 
tion a  vertical  projection,  a  vertical  section,  and  a  projection 
of  the  vein  itself.  In  common  practice  the  survey  of  the  mine 
means  nothing  more  than  a  determination  of  the  amou 
position  of  excavation. 

To  survey  the  mine  properly  it  is  essential  that  some  gen- 
eral plan  be  first  laid  out  and  that,  so  far  as  possible,  tl 
be  closely  followed.     In  traversing  drifts,  irregularities  should 
be  noted  so  that  if  of  importance  they  will  appear  on  tl 
all  openings  should  be  noted. 

In  surveving  coal  mines,  the   angle  at  which  rooms  are 
turned  off  should  be  measured,  the  rooms  properly  located  wit 
re-ard  to  the  entry,  all  dimensions  carefully  taken  and  all  oper 

^:  4  <*-/. 

As  2 


32  A  STUDY  IN  MINE  SURVEYING  METHODS 

ings  correctly  located.  When  openings  are  closed,  gobbed  or 
bratticed  they  should  appear  so  in  the  notebook.  Even  though 
such  features  are  not  to  be  mapped,  the  surveyor  should  make 
his  book  a  record  of  actual  conditions,  in  the  mine  when  the 
survey  is  made. 

In  surveying  a  longwall  mine,  it  is  necessary  to  show  the 
roads  that  are  open  and  the  working  face.  Points  about  40 
feet  apart  are  located  and  the  face  is  then  drawn  in  the  notebook. 
The  traverse  may  be  carried  along  the  face  but  this  is  gen- 
erally very  dangerous  and  points  established  are  so  near  to  the 
working  face  that  they  will  be  blown  out  by  blasting. 

In  surveying  large  stopes  it  is  often  impossible  to  use  the 
transit.  Special  methods  must  then  be  adapted.  The  various 
types  of  clinometers  and  needles  on  cords  have  been  successfully 
used.  Hand  compasses  or  hand  transits  are  then  of  great 
assistance.  A  few  hours'  work  with  the  Brunton  will  show  its 
applicability  to  this  grade  of  work.  The  method  of  off-setting 
with  tapes  is  commonly  used- in  metalliferous  mines. 

There  is  considerable  difference  in  the  method  of  conduct- 
ing a  survey  when  one  is  in  the  regular  employ  of  a  company 
and  when  one  is  doing  only  custom  work.  More  permanent 
stations  should  be  established  in  the  former  case  than  in  the 
latter. 

The  field  book  should  be  a  regular  and  accurate  record  of 
the  work  of  the  surveying  party  irrespective  of  the  continuity 
of  the  work,  or  several  books  should  be  used  so  that  a  con- 
tinuous record  may  be  kept  in  one  book  of  the  work  in  one 
mine  or  one  section  of  the  mine.  Notes  should  be  so  well 
taken  that  they  can  be  worked  up  "cold,"  that  is,  any  time  after 
the  survey  is  made  by  any  one.  It  is  advisable  to  keep  the  map 
work  up  close  to  field  work.  Very  often  surveys  must  be  made 
at  regular  intervals.  Where  such  is  not  the  case,  and  the  sur- 
veying party  does  the  mapping,  each  day's  work  should  be  com- 
pleted before  another  is  begun.  That  is,  all  calculations  of 
traverse  should  be  made  the  same  day  the  field  work  is  done. 
This  often  works  hardship  to  the  instrument  man,  but  after  sys- 
tematizing his  work  he  will  find  it  easy  and  will  want  to  do  it. 
Mapping  can  be  reserved  for  odd  days. 

Side  notes  can  be  kept  best  by  using  the  right  hand  page 
of  the  field  book  for  sketches,  the  left  hand  for  angles,  dis- 
tances, etc.  Sketching  and  all  notes  should  begin  at  the  bottom 
of  the  page  and  follow  up  the  page.  The  center  line  of  the  page 
should  be  taken  as  the  line  of  traverse.  Sketch  to  a  convenient 
scale,  and  do  not  crowd  the  notes.  Always  take  enough  meas- 
urements and  sketch  carefully.  Some  engineers  do  not  attempt 
to  show  to  scale  distances  from  the  traverse,  but  put  in  dimen- 
sions so  that  the  notes  can  be  easily  interpreted. 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING      jj> 

GEOGNOSY. 

Preliminary  to  beginning  underground  operations  it  is 
often  necessary  that  the  location  and  extent  of  the  deposit  to 
be  mined  should  be  determined.  When  there  is  an  outcrop,  this 
can  generally  be  more  easily  accomplished  than  when  there  is 
no  surface  indication. 

Stratified  Deposits.  Flat  seams  of  coal  are  often  so  cut  by 
streams  that  an  outcrop  may  be  traced  for  many  miles.  A  tra- 
verse may  then  be  run  along  the  outcrop  to  determine  the 
boundaries  of  the  coal.  Often  the  outcrop  of  an  overlying 
measure  is  taken  as  an  indication  of  coal  and  it  is  then  common 
to  run  a  so-called  "crop  line"  along  the  outcrop.  When  the 
measures  are  intersected  by  streams  large  tracts  of  coal  are 
often  platted  in  this  way.  When  the  tract  is  not  completely 
severed  from  the  adjoining  area,  it  becomes  necessary  to  put 
down  bore-holes.  These  will  show  the  depth  of  the  coal  horizon 
and  together  with  the  crop  line  will  serve  to  locate  and  bound 
the  tract.  When  the  measures  are  inclined  and  outcrop  in  a 
flat  country,*  the  outcrop  should  be  traversed  and  bore-holes 
should  be  put  down  to  intersect  the  productive  measures.  The 
depth  of  the  holes  and  their  position  with  regard  to  the  outcrop 
being  known,  the  productive  area  or  acreage  can  be  platted. 

When  the  measures  are  overturned  or  vertical  at  the  out- 
crop and  then  slope  off  to  horizontal  it  becomes  more  difficult 
to  estimate  acreage  and,  finally,  the  tonnage.  Faults  frequently 
displace  measures  so  that  calculations  are  unreliable.  The  fault 
plane,  throw,  etc.,  must  be  positively  established  before  any  esti- 
mates or  plats  can  be  made.  In  many  districts  in  the  central 
states,  the  coal  measures  are  horizontal  and  covered  with  glacial 
debris.  The  coal  has  at  places  been  completely  eroded,  at  oth- 
ers is  covered  with  but  a  few  feet  of  rock  and  at  others  by  several 
hundred.  The  continuity  of  the  coal  can  be  determined  only  by 
very  numerous  drill  holes,  as  many  as  six  hundred  to  the  section 
being  common  practice. 

Outcropping  veins  should  be  traversed,  their  strike  and  dip 
determined,  and  their  intersections  and  any  disturbing  fault 
planes  carefully  located.  When  there  is  no  outcrop,  drill  holes 
may  be  put  down  to  intersect  veins.  Knowing  the  location, 
depth  and  angle  of  these  holes  to  intersect  the  vein,  the  position 
of  the  vein  is  determined  and  the  mineral  acreage  may  be  ap- 
proximately determined. 

Masses  or  lenses'  of  ore  appearing  on  the  surface  should  be 
surveyed  and  drill  holes  located  at  regular  intervals.  The  holes 
being  vertical,  their  depth  and  location  being  known  and  platted 


34  A  STUDY  OF  MINE  SURVEYING- METHODS 

the  volume  in  the  mass  may  be  calculated  and  the  tonnage  esti- 
mated. When  masses  or  lenses  do  not  outcrop ;  drill  holes  should 
be  put  down  to  intersect  the  mineral.  The  depth  at  which  the 
drill  enters  and  leaves  the  ore  body  being  noted  for  each  hole 
and  each  hole  being  properly  located  on  a  contoured  map,  the 
volume  of  the  mass  can  be  determined. 

Alluvial  deposits  should  be  carefully  mapped  and  drill  holes 
so  located  and  mapped  that  the  volume  of  material  as  well  as  the 
extent  and  depth  of  rich  strata  may  be  determined. 

The  importance  of  surveying  in  the  work  preliminary  to 
mining  operations  can  be  readily  seen.  No  legitimate  mining 
enterprise  is  attempted  without  a  fair  knowledge  of  the  extent 
of  the  body  upon  which  operations  are  to  be  carried  on.  A 
complete  contoured  map  is  always  of  great  advantage  to  the 
engineer  who  is  locating  a  deposit. 

DRILL  HOLES. 

It  is  frequently  assumed  that  bore  holes  are  straight ;  that 
is,  if  started  vertical,  they  continue  so,  or  if  started  on  a  known 
angle  they  continue  on  that  angle.  This  is  seldom  the  case,  for 
the  holes  are  deflected  from  their  course.  This  is  more  likely 
to  occur  in  vertical  holes  with  the  diamond  drill  than  with  the 
percussion  drill.  However  with  the  percussion  drill  when  the 
rods  are  not  very  long,  the  rod  tends  to  work  to  one  side  and 
may  soon  be  deflected  from  the  vertical.  The  falling  weight, 
however,  has  a  tendency  to  straighten  the  hole.  When  the 
diamond  drill  is  used  for  an  inclined  hole  it  is  almost  impossible 
to  maintain  the  desired  angle  because  the  drill  rods  are  of  a 
smaller  diameter  than  the  bit  and  will  lie  against  the  bottom  or 
side  of  the  hole  and  by  this  deflection  the  face  of  the  bit  is  in- 
clined from  the  proper  bearing.  In  order  to  ascertain  the  course 
that  has  been  taken  by  a  bore  hole  it  is  necessary  to  make  a 
survey  just  as  it  is  necessary  to  survey  a  tunnel.  Many  diffi- 
culties must  be  overcome,  and  to  this  end  many  ingenious  de- 
vices have  been  adapted.  Nolten's  instrument  consists  essential- 
ly of  a  glass  cup  in  which  is  placed  hydrofluoric  acid.  When 
the  cup  is  placed  in  a  bore  hole  in  an  inclined  position,  the  acid 
will  attack  that  part  of  the  glass  below  the  level  of  the  acid. 
A  line  will  then  mark  the  angle  of  inclination  of  the  glass  cup. 
While  the  acid  is  being  lowered  into  the  hole  the  acid  will  shake 
about  and  will  leave  no  clear  mark  upo^i  the  glass ;  when  it  has 
reached  the.  required  depth,  if  it  is  allowed  to  remain  unmoved 
for  half  an  hour,  the  acid  will  etch  a  permanent  record  of  the 
inclination  of  the  glass  and  also  of  the  tube  in  which  it  is  fixed. 
In  order  to  record  the  direction  in  which  the  hole  is  proceeding, 
in  case  it  is  not  perfectly  vertical,  another  instrument  is  com- 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING      jj 

bined  with  this  one  and  fixed  in  the  same  tube.  This  instru- 
ment consists  of  a  compass  needle  free  to  revolve  in  a  horizontal 
plane  on  a  vertical  pivot,  and  of  a  watch  which  can  be  set  to 
operate  a  lever,  so  that  the  needle  can  be  clamped  at  the  exact 
time  at  which  the  watch  is  set.  When  lowered  into  the  hole, 
the  needle  after  being  allowed  to  come  to  rest  is  clamped,  and 
will  show  the  direction  of  inclination  because  the  compass  is  fas- 
tened to  the  tube. 

Ordinary  gelatine  is  easily  melted  when  immersed  in  hot 
water  and  solidifies  again  at  70°  F.  When  melted  it  takes  sev- 
eral hours  to  stiffen.  A  clinometer  and  compass  placed  in  a 
tube  containing  melted  gelatine  and  lowered  into  a  bore  hole 
will  show  the  direction  and  inclination  if  the  gelatine  is  allowed 
to  cool. 

Various  other  devices  may  be  used.  It  has  been  found  that 
in  a  depth  of  370  feet  a  bore  hole  had  deviated  37.5  feet  in  a 
horizontal  direction  from  the  vertical.  It  cannot  be  assumed, 
then,  that  bore  holes  are  vertical  when  deep  deposits  are  being 
prospected.  In  order  to  block  out  the  ore  body,  holes  must  be 
platted  in  their  true  position.  Frequently  a  diamond  drill  is  set 
up  underground  and  holes  at  various  angles  are  used  to  explore 
the  adjacent  ground.  Also  in  driving  drifts  towards  abandoned 
mines  it  is  necessary  to  carry  holes  ahead  and  to  the  sides  of 
the  drifts  in  order  to  avoid  breaking  into  bodies  of  water  or  gas. 

LOCATING  OPENINGS  AND  MINE  PLANT. 

In  locating  and  blocking  out  ore  bodies  various  openings 
are  necessary.  Samples  must  be  taken  in  order  to  determine 
the  quality  of  the  ore.  Openings  provide  the  means  for  getting 
such  samples  and  for  determining  the  quantity  of  material  that 
can  be  mined.  Such  openings  must  be  carefully  located.  By 
means  of  bore  holes  samples  can  be  obtained  from  ore  bodies 
at  considerable  depth.  Shafts,  tunnels  and  drifts  better  serve 
this  purpose  but  the  cost  being  much  greater  these  generally 
give  way  to  the  bore  holes  for  systematic  and  extended  explor- 
ation. 

The  extent  and  depth  of  the  ore  body  being  determined  by 
careful  surveys  of  the  exploratory  openings,  the  sites  for  per- 
manent openings  and  buildings  are  surveyed.  A  contoured  map 
is  always  of  great  service  in  laying  out  the  mine  plant.  Mine 
openings  should  be  so  placed  that  surface  water  will  not  run 
into  the  mine— that  a  very  high  building  will  not  be  necessary 
to  secure  fall  enough  to  run  the  product  of  the  mine  to  the  mill 
or  into  railroad  cars,  and  that  there  is  sufficient  clump  room. 
When  upon  the  side  of  a  mountain,  openings  must  be  placed 
out  of  the  paths  of  rock  and  snow  slides.  The  surface  plant 


j6  A  STUDY  OF  MINE  SURVEYING  METHODS 

being  located,  the  underground  workings  may  be  laid  out. 
When  a  flat  coal  seam  is  to  be  mined,  large  companies  generally 
make  a  plan  showing  how  openings  are  to  be  driven  and  how 
working  places  are  to  be  located.  When  seams  dip  consider- 
ably, it  becomes  necessary  to  establish  roadways  on  grade.  Gen- 
erally these  can  be  laid  out  on  paper.  When  the  conditions  af- 
fecting the  method  of  working  are  known,  ore  bodies  may  be 
blocked  out  similarly.  That  is,  if  we  krtow  a  vein  is  regular 
and  dips  at  a  certain  angle,  levels  and  stopes  may  be  platted 
and  workings  made  to  conform  with  this  plan.  Such  plans 
are,  of  course,  ideals  and  may  not  be  attained,  but  it  is  always 
well  to  have  in  mind*  such  ideals  and  then  endeavor  to  carry 
out  the  system  planned.  If  the  tract  has  been  properly  ex- 
plored without  the  use  of  drifts,  tunnels  and  shafts,  openings 
may  be  so  located  that  with  a  minimum  amount  of  dead  work 
a  maximum  tonnage  may  be  produced  at  a  low  operating  ex- 
pense. Faults,  irregularities,  old  stream  channels,  poor  coal, 
poor  roof  and  old  workings  may  be  avoided.  Some  companies 
in  Pennsylvania  require  all  openings  to  be  driven  straight 
and  rooms  to  be  driven  at  a  given  angle  irrespective  of  local 
conditions.  In  laying  out  the  mine  workings  on  paper,  proper 
pillars  should  be  left  for  shafts,  roadways,  boundaries  and 
buildings.  Failure  to  determine  the  position  of  buildings  on 
the  surface  \vith  regard  to  mine  openings  has  often  been  re- 
sponsible for  disasters.  Witness  the  cave  in  at  the  Negaunee 
mine  which  incapacitated  the  hoists  for  two  shafts,  thus  pre- 
venting the  immediate  removal  of  debris  in  order  to  release 
the  miners. 

The  mine  surveyor  then  is  largely  responsible  for  the  laying 
out  of  the  mine  and  arrangement  of  the  mine  plant. 

SHAFT  SINKING. 

In  sinking  large  shafts  the  surveyor  generally  plays  an 
important  part.  The  shaft  must  be  kept  vertical  or  upon  a 
given  pitch.  When  the  shaft  is  sunk  on  the  lode  regardless  of 
change  of  dip,  it  becomes  necessary  to  place  frequent  rollers 
or  pulleys  to  carry  the  hoisting  rope.  Many  companies  today 
in  sinking  large  shafts  decide  dpon  a  given  angle  for  the 
shaft  and  sink  regardless  of  walls.  The  surveyor  must  then 
not  only  keep  the  work  progressing  in  the  proper  direction 
but  establish  points  by  which  the  proper  vertical  angle  may  be 
maintained. 

Record  of  the  depth  must  be  given  regularly  and  points 
located  so  that  the  plats  or  stations  may  be  cut  at  the  proper 
intervals.  When  sinking  has  progressed  to  a  lower  level  and 
the  plat  has  been  cut  the  timbermen  require  the  surveyor  to 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING      37 

locate  for  them  by  elevation  the  sleepers  to  carry  the  skip 
rails.  In  order  to  do  this  the  surveyor  proceeds  as  follows: 
The  transit  is  set  up  over  the  rail  at  a  known  point,  the 
shortest  distance  is  measured  from  the  axis  of  the  telescope,  — 
when  the  angle  of  the  shaft  is  large  the  top  telescope,  — to  the 
sleeper;  at  about  100  feet  back  a  leveling  rod  with  the  target 
set  at  the  distance  just  measured  at  the  instrument  is  placed 
on  the  sleeper  and  held  at  right  angles  to  the  sleeper ;  the  tele- 
scope is  then  sighted  on  the  target  and  the  vertical  angle  read ; 
this  should  be  the  established  shaft  angle.  If  it  'checks  pro- 
perly, the  rod  reading  is  recorded  and  the  rodman  goes  down 
the  shaft  to  the  point  at  which  marks  for  setting  sleepers  are 
desired.  He  places  his  rod  along  the  stulls  or  shaft  timbers 
so  that  the  rod  makes  a  right  angle  with  the  established  line 
of  the  shaft.  The  transitman  has  the  rodman  place  the  target, 
clamped,  as  already  noted,  in  the  line  of  the  telescope  when 
set  at  the  proper  vertical  angle.  The  zero  of  the  rod  then 
determines  the  proper  point  for  the  top  line  of  the  sleeper. 

Along  shafts  which  are  not  straight  as  previously  noted, 
pulleys,  sheaves  or  rollers  must  be  properly  placed.  It  fre- 
quently falls  to  the  lot  of  the  surveyor  to  determine  the  proper 
points  for  such  rollers.  The  proper  line  for  the  rope  must 
then  be  determined  if  possible  analytically ;  generally,  how- 
ever, a  few  experiments  will  show  where  the  pulley  is  needed. 

TUNNELLING. 

In  driving  a  tunnel  for  prospecting  purposes  or  for  trans- 
portation, the  surveyor  must  give  the  direction,  distance  and 
grade.  The  direction  may  be  established  by  three  points  placed 
on  lines.  One  of  these  points  should  be  a  permanent  station 
and  not  less  than  thirty  feet  from  the  breast,  the  other  two 
about  six  feet  apart  and  one  not  less  than  ten  feet  from  the 
breast.  By  hanging  plumb  lines  from  these  stations  the  work- 
men can  properly  align  their  work.  Unless  precautions  are 
takn  the  walls  will  not  be  driven  straight.  The  walls  of  the 
tunnel  should  be  equidistant  from  the  established  line,  or  some 
given  distance.  Timbers  should  be  set  on  line. 

"In  very  long  tunnels  excavated  under  high  mountains 
more  elaborate  methods  have  to  be  adopted  for  locating  the 
center  line.  The  theodolites  employed  must  be  of  large  size: 
in  ranging  the  center  line  of  the  St.  Gothard  tunnel,  the  theo- 
dolite used  had  an  object  glass  eight  inches  in  diameter.  Instead 
of  the  ordinary  mounting  a  masonry  pedestal  with  a  perfectly 
level  top  is  employed  to  support  the  instrument  during  the  obser- 
vations. The  location  is  made  by  means  of  triangulation.  The 
various  .operations  must  be  performed  with  the  greatest  ac- 


jS  A  STUDY  OF  MINE  SURVEYING  METHODS 

curacy,  and  repeated  several  times  in  such  a  way  as  to  reduce 
the  errors  to  a  minimum,  since  the  final  meeting  of  the  head- 
ings depends  upon  their  elimination." 

"The  triangulation  was  compensated  according  to  the 
method  of  least  squares.  The  probable  error  in  the  fixed  direc- 
tion was  calculated  to  be  0.8"  of  arc.  From  this  it  was  assumed 
that  the  probable  deviation  from  the  true  center  would  be  about 
two  inches  at  the  middle  of  the  tunnel,  but  when  the  headings 
finally  met  this  deviation  was  found  to  reach  eleven  inches."* 

The  cross  section  of  a  large  tunnel**  may  be  taken  by  a 
method  of  polar  co-ordinates.  A  light  brass  protractor  in  a 
vertical  plane  is  mounted  on  a  tripod ;  to  this  protractor  is 
secured  a  light  measuring  rod,  graduated  to  tenths,  which 
slides  upon  a  rest  on  the  face  of  the  protractor.  Points  in  the 
cross  section  are  measured  by  setting  the  plane  of  the  pro- 
tractor at  right  angles  to  the  axis  of  the  tunnel  and  then  slid- 
ing the  rod  out  until  it  touches  the  wall.  Read  the  length  on 
the  rod  and  record  the  angle,  and  so  on  for  any  number  of 
points  on  the  circumference  of  the  tunnel  section. 

In  order  to  properly  drain  the  tunnel  and  that  a  uniform 
grade  in  favor  of  loaded  cars  may  be  maintained,  the  surveyor 
should  regularly  establish  grade  points  for  the  foreman. 

MINE  WORKINGS. 

In  well  planned  mines,  the  surveyor  must  almost  daily 
establish  points  for  the  shift  boss  or  foreman  in  order  that 
rooms,  stopes,  raises  or  breakthroughs  may  be  driven  as 
planned.  In  some  states  breakthroughs  must  be  driven  at  a 
minimum  distance  apart.  The  surveyor  must  keep  the  mint 
so  surveyed  that  he  can  quickly  establish  such  points.  It  is 

good  practice  to  set  points   for  the  center  line  of  openings, 
enerally  it  is  necessary  to  give  such  points  at  first  only  tem- 
porarily as  stations  established  so  near  a  working  face  will  be 
disturbed ;  after  the  work  has  proceeded  sufficiently  permanent 
points  may  be  put  in. 

pji-Jp          CURVES  AND  CONNECTIONS. 

It  is  often  necessary  to  drive  a  curved  entry  in  a  mine  in 
which  rope  or  motor  haulage  is  used  and  especially  where  cars 
must  travel  rapidly  from  the  side  entries  into  th%e  main  entry. 
These  curves  are  often  quite  sharp  and  are  described  with 
regard  to  their  radius  rather  than  to  curvature  in  degrees. 
The  method  of  laying  out  these  curves  differs  from  railroad 

*Prelinis  Tunneling,  p.  10.       **A.  S.  C.  E.  XXIII,  17. 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING      39 

practice  only  in  that  all  points  cannot  be  established  at  one 
time.  Points  should  be  set  daily  by  which  the  miners  can 
drive.  Points  should  not  be  more  than  ten  feet  apart. 

One  of  the  most  important  phases  of  mine  surveying  and 
probably  what  requires  most  care  is  a  survey  for  openings  to 
connect  two  given  or  assumed  points.  Numerous  problems 
will  arise  upon  which  will  depend  the  reputation  of  the  sur- 
veyor. The  principal  precautions  that  should  be  taken  are  (a) 
the  adjustment  of  the  instruments,  (b)  the  complete  survey 
should  be  made  by  one  squad,  (c)  all  stations  should  be  per- 
manent if  possible,  (d)  all  measurements  and  readings  should 
be  checked.  The  surveyor  may  be  called  upon  to  establish  the 
line  for 

(a)  a  railroad  tunnel  driven  on  grade  from  both  ends, 

(b)  a  railroad   tunnel   driven   from  both   ends   and   from 
shafts  sunk  along  the  line  of  the  tunnel, 

(c)  a  mining  tunnel  to  connect  with  a  shaft  01  vice  versa, 

(d)  a  drill  hole  to  intersect  mine  workings, 

(e)  a  cross  cut  to  connect  workings  on  adjacent  veins, 

(f)  a  raise  to  connect  a  given  point  on  a  level  and  a  shaft 
or  another  level,  and 

(g)  air  courses  to  connect  working  places. 

OPENINGS  TO  INTERSECT  VEINS. 

In  many  of  the  important  mining  districts  engineers  have 
been  called  upon  to  solve  various  problems  which  require  the 
application  of  that  division  of  geometry  generally  known  as 
descriptive  geometry.  Certain  assumptions  must  be  made  in 
all  cases  but  the  results  obtained  prove  of  considerable  value 
in  that  no  greater  error  can  occur  when  conditions  as  noted 
continue,  and  the  results  of  such  solutions  are  generally  better 
than  guesses. 

In  the  Cripple  Creek,  San  Juan  and  Clear  Creek  districts, 
shoots  and  zones  of  ore  occur  adjacent  to  the  intersections  of 
veins.  Practical  miners  say  that  "invariably"  will  ore  be  found 
at  these  "junctions"  and  that  it  is  always  advisable  to  drive  to 
such  points.  Many  openings  are  put  down  in  quest  of  such 
intersections  when  it  is  supposed  that  they  exist  and  many  feet 
of  work  show  that  often  the  miner  has  "stayed  with  the  ore" 
when  he  might  have  taken  a  short  cut  and  saved  much  money 
and  labor. 

The  following  assumptions  should  be  made  in  working  out 
problem?  graphically:  (a)  The  surface  is  assumed  to  be  a  hori- 
zontal plane,  (b)  Veins  are  planes  of  uniform  dip;  intersec- 
tions of  veins  are  straight  lines;  thickness  of  veins-  is  not  to 
be  considered,  (c)  Shafts  on  veins  will  be  straight,  (d)  Ex- 


40  A  STUDY  OF  MINE  SURVEYING  METHODS 

cept  when  the  grade  is  specified,  tunnels  are  horizontal,  also 
drifts,  (e)  Dimensions  of  shafts  and  tunnels  should  not  be 
considered,  that  is,  openings  are  considered  to  be  straight  lines 
(f)  All  inclined  shafts  to  be  the  shortest  possible.  In  the 
solution  of  problems  in  practice,  the  scale  used  should  be  such 
that  the  errors  of  platting  do  not  materially  change  the  results. 

It  is  very  difficult;  in  fact  almost  impossible  except  in 
stratified  measures,  to  solve  problems  of  faulting.  In  all  cases 
certain  assumptions  must  be  made.  If  actual  conditions  are 
not  known  and  the  continuity  of  the  vein  or  seam  is  not  known, 
any  solution  cannot  be  accepted.  In  all  cases  results  of  such 
solutions  can  be  given  as  only  probable  or  possible.  Change 
of  dip  or  strike,  faults  or  other  irregularities  may  easily  render 
such  solutions  valueless. 

Many  of  these  problems  the  engineer  can  solve  analytic- 
ally and  can  check  the  graphical  method.  Having  determined 
the  proper  solution  for  any  problem  similar  to  those  given  the 
surveyor  has  then  only  to  establish  points  and  from  time  to 
time  check  up  the  alignment  of  the  opening  driven  to  make 
the  connection. 

GEOLOGICAL  IRREGULARITIES. 

As  previously  noted  all  irregularities  should  be  noted  and 
mapped.  Fault  planes,  horses,  rolls,  water  courses,  etc.,  if 
properly  mapped  in  one  level  and  drift  may  be  anticipated  in 
driving  new  openings.  Intersections  of  veins  may  be  opened 
up  in  lower  levels  without  undue  loss  of  time  if  they  have  been 
carefully  located  in  the  upper  workings.  The  dip  and  strike  of 
veins  should  always  be  noted  even  though  there  be  not  any 
values  in  sight.  In  surveying  tunnels  all  veins  that  are  cut 
should  be  mapped  and,  if  possible,  identified  and  described. 
Failure  to  note  all  the  veins  cut  has  in  many  cases  resulted  in 
much  useless  dead  work.  The  character  of  walls  and  roof 
should  be  noted,  as  well  as  the  thickness  of  the  vein. 

DRAINAGE. 

The  surveyor  is  frequently  called  upon  to  establish  a  drain- 
age system  for  a  mine.  In  flat  seams,  he  must  then,  if  he  has 
not  already  done  so,  run  a  line  of  levels  and  determine  the 
proper  points  at  which  to  establish  small  sumps  from  which 
the  mine  water  shall  be  conducted  to  the  main  sump.  Some- 
times it  is  possible  to  drain  all  the  water  into  the  old  workings. 
A  complete  map  of  old  workings  is  necessary  in  order  that 
the  volume  of  water  that  can  be  stored  may  be  determined. 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       ji 

Dams  should  then  be  placed  where  they  may  have  good  pillars 
to  hold  them  in  place.  Several  of  the  large  coal  companies 
carry  all  water  in  ditches  in  the  back  entries.  Some  of  the 
Michigan  copper  companies  handle  all  the  mine  water  through 
one  shaft.  This  necessitates  that  there  be  an  opening  con- 
necting the  mines  so  that  water  can  run  freely  from  any  point 
to  the  drainage  shaft.  Recently  at  Cripple  Creek  a  tunnel  has 
been  driven  in  order  to  drain  a  number  of  mines.  This  tunnel 
was  driven  on  line  and  grade  to  tap  flooded  workings.  There 
were  three  shafts  on  the  line  of  the  tunnel  and  in  all,  six  points 
of  attack.  The  importance  of  an  accurate  survey  can  be  readily 
seen. 

Impervious  strata  should  be  noted  in  drilling  in  order  that 
the  system  of  mining  may  be  properly  adapted  to  conditions. 
This  is  also  important  in  locating  sumps.  The  water  level  of 
a  district  or  mine  should  be  determined  and  mapped  and  this 
can  best  be  accomplished  only  when  complete  records  are  kept 
of  all  surveys  and  conditions  at  the  time  of  survey. 

When  mine  openings  are  driven  through  old  stream 
channels,  as  in  the  coal  fields  of  some  of  the  central  states,  it 
is  at  times  possible  to  discharge  the  mine  water  into  the  old 
channels.  However  during  the  wet  season  of  the  year  these 
channels  become  filled  with  water  and  flood  the  mine.  It  is 
generally  advisable  to  line  the  openings  so  that  water  cannot 
pass  through. 

HAULAGE. 

Important   road   ways   should  be   driven  on   grades   which 

are  adapted  to  the  system  of  haulage.     The  grade  of  tunnels 

has  already  been  spoken  of.     In  mining  in  flat  seams  very  fre- 

quently rolls  are  encountered  and  these  must  be  cut  out.     On 

pitching  seams  roadways  should  be  driven  on  grade.     For  rope 

haulage  the  grade  need  not  be  regular,  but  if  possible  all  irreg- 

ularities should  be  eliminated.     The  surveyor  is  called  upon  to 

^._  establish  points  so  that  the  work  may  progress  in  the  proper    . 

/tj^if^cti^li,  to  put   in   curves   where  necessary   and  to   establish  ^ 

/grade's.' 


fo*-  MAPPING. 

''•£     /?<"'-/  ^'9 

Two   systems   are   used   in   mapping  mines,'  total'  latitudes! 

and   departures,   and   by  means   of  the   protractor.     Important 
courses   as   in   the   main   entries   and   shafts   should   always    be  *• 
platted  by  latitudes  and  departures  and  checked  by  the  pro4  £^ 
tractor.    "Work   with    the   protractor   progresses    much    more\ 
rapidly  than  with  latitudes  and  departures  but   it  is  not  very\ 
accurate. 


4 


42  A  STUDY  OF  MINE  SURVEYING  METHODS 

The  size  of  sheet  necessary  for  mapping  the  mine  sur- 
veyed and  the  probable  extensions  that  can  be  economically 
made  from  the  main  opening  should  be  laid  out  in  squares  five 
to  ten  inches  on  a  side  depending  on  the  scale. 

Coal  mines  are  seldom  made  smaller  than  one  inch  to  one 
hundred  feet.  Metalliferous  mines  may  be  made  to  almost  any 
scale;  generally  a  large  map  say  one  inch  equal  to  thirty  feet 
is  drawn  to  show  stopes,  rooms,  etc.,  while  another,  one  inch 
equal  to  sixty,  one  hundred  or  two  hundred  feet,  will  show  the 
shafts  and  drifts.  Several  states  require  that  map  be  made  a 
given  scale. 

For  beds,  horizontal  or  nearly  so,  a  plan  is  sufficient.  The 
following  quotations  state  briefly  good  practice  for  metalliferous 
mines:  "The  survey  is  properly  shown  by  at  least  three  maps: 
first,  the  plan  or  projection  on  a  horizontal  plane ;  second,  the 
longitudinal  section,  generally  the  projection  on  a  vertical  plane 
coinciding  as  near  as  may  be  with  the  general  direction  of  the 
levels;  third,  the  transverse  section  or  projection  on  a  vertical 
plane  at  right  angles  to  the  longitudinal  one.  The  maps  should 
have  a  title  giving  the  name  of  the  mine  and  location  by  mining 
district,  county  and  state ;  also  there  should  appear  the  name 
of  the  surveyor,  date  of  survey,  meridian  used,  and  scale.  The 
map  should  be  on  cloth  backed  paper  or  tracing-cloth,  and  may 
show  on  the  plan  the  position,  number,  and  elevation  of  the 
permanent  stations  with  the  bearing  and  length  of  the  lines 
joining  them  or  the  coordinates  of  the  stations,  according  to 
the  system  used.  The  advisability  of  showing  these  data  on 
the  map  depends  on  the  use  that  it  to  be  made  of  them  and 
must  be  decided  according  to  the  nature  of  the  case."* 

The  best  practice  today  requires  that  all  notes  should  be 
copied  from  the  field  books  and  filed  together  with  all  cal- 
culations so  that  at  any  time  reference  may  be  made  to  any 
part  of  any  survey.  Calculations  should  be  made  by  the  use  of 
logarithms  and  so  arranged  that  any  one  can  check  the  work. 

The  record  book  may  be  ruled  in  the  following  form  ex- 
tending across  one  or  two  pages: 


| 

£ 

^ 

*• 

Q 

Q 

< 

1 

Latitude 

o 

o 
Q 

TOTAL 

1 

j 

d 

_!^_ 

I 

^> 

s 

~ 

+|- 

-f 

— 

•Johnson's  "Theory  and  Practice  of  Surveying." 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       43 

Side  notes  should  be  preserved  in  the  field  book  and  may  be 
inked  in  in  order  to  make  them  more  legible. 

Certain  schemes  once  adopted  should  be  continued.  An 
inspection  of  maps  from  various  districts  will  show  how  varied 
is  the  practice.  One  company  will  place  the  date  of  a  survey 
at  the  last  station  made  by  that  survey  on  each  shaft  and 
opening;  another  will  use  a  letter  or  number  to  represent  a 
survey ;  another  will  use  colors  on  the  maps,  a  distinguishing 
color  for  each  survey.  Practice  in  showing  worked  out  ground 
is  even  more  varied.  The  common  methods  are  as  follows: 
(a)  Printing  on  the  map  the  phrase  "worked  out"  over  such 
portions  of  the  mine ;  (b)  by  coloring  the  portions  different  from 
the  permanent  openings  and  pillars ;  (c)  by  hatching  the  bound- 
aries of  worked  out  portions ;  (d)  by  dotting  with  inks. 

Several  of  the  largest  companies  photograph  their  maps 
each  year  in  order  to  keep  a  permanent  and  convenient  record 
of  the  progress.  In  such  cases  it  is  necessary  to  mark  each 
year's  work  so  that  it  will  show  on  the  plat. 

Frequently  mine  maps  must  be  produced  in  court  as  evi- 
idence.  In  all  cases  such  maps  should  be  so  complete  and 
so  carefully  prepared  that  no  questions  can  arise  in  regard  to 
the  accuracy  of  the  work  of  the  engineer.  Special  maps  and 
diagrams  should  be  made  on  a  large  scale  in  order  to  better 
illustrate  specific  points  in  question. 

Models  may  be  made  to  show  parts  of  the  mine,  the  com- 
plete workings,  and  the  relative  position  of  openings,  excava- 
tions and  property  lines.  Models  should  be  on  such  a  scale 
that  dimensions  can  be  readily  appreciated.  Only  openings 
may  be  shown,  or,  the  entire  territory  and  ground  included 
may  be  represented  by  wood  or  glass.  Sedimentary  deposits 
sho'uld  be  represented  by  sheets  of  glass  or  wood  which  can 
be  easily  handled  and  placed  together  to  show  actual  con- 
ditions. A  skeleton  of  sheet  metal,  wire  or  tubing  may  repre- 
sent the  various  openings.  Sheets  of  glass  may  be  used  to 
represent  the  veins  and  excavations  shown  in  colors  on  the 
glass.  Vertical  or  horizontal  sheets  of  glass  may  be  used  and 
after  the  shaft  has  been  located  on  these  the  adjacent  workings 
may  be  be  projected. 

CALCULATION  OF  VOLUMES  AND  ASSAY  PLANS. 

The  estimation  of  volumes  and  tonnage  of  ore  in  place 
or  in  stopes  is  one  of  the  most  important  parts  of  a  consulting 
engineer's  work,  and  he  must  adopt  a  system  of  work  which 
shall  be  rapid  and  at  the  same  time  sufficiently  accurate  for 
his  purpose.  A  good  engineer  cannot  be  satisfied  with  any- 
thing but  absolute  accuracy,  but  generally  sufficient  time  is 


A  STCDY  OF  MINE  SURVEYING  METHODS 


not  available  for  the  most  accurate  work.  Chapter  XIII.  of 
Johnson's  Surveying  is  given  to  a  consideration  of  the  most 
accurate  methods  for  the  measurement  of  volumes,  to  \vhich 
work  the  student  is  referred.  Practicing  engineers  persist 
in  the  use  of  approximate  methods,  among  which  the  most 
popular  is  the  one  known  as  the  "mean  end  areas  formula'' 
which  Johnson  condemns. 

In  behalf  of  the  prismoidal  formula  its  extreme  accuracy 
is  urged,  while  in  behalf  of  the  mean  ends  formula  its  sim- 
plicity and  rapidity  in  use  are  undeniable.  In  mining  work 
it  is  not  possible  to  get  frequent  cross  sections.  In  estimating 
ore  bodies,  unbroken  blocks  larger  than  100'  x  100'  should  not 
be  considered  when  it  is  known  that  the  ore  body  is  not  reg- 
ular. Winzes,  raises  and  drifts  should  be  driven  to  divide  the 
ore  body  into  small  blocks.  Each  mine  has  its  special  problems 
and  no  fixed  rule  can  be  stated,  only  this,  always  underesti- 
mate the  tonnage  in  blocks  of  ore.  In  all  cases  an  accurate 
map,  about  one  inch  to  thirty  feet,  should  be  used  and  meas- 
urements of  the  vein  and  ore  body  taken  every  five  feet  for 
accurate  work.  Such  measurements  should  be  noted  on  the 
map  at  the  point  corresponding  to  the  place  where  the  meas- 
urements were  taken.  Samples  should  also  be  taken  at  these 
points.  Methods  of  sampling  cannot  be  discussed  in  this  paper. 
Almost  all  the  mines  of  the  Rand  keep  assay  plans.  An  assay 
plan  of  a  mine  is  any  map,  —  not  necessarily  a  plan,  —  which 
shows  accurately  the  dimensions  and  value  of  the  ore  bodies 
at  such  intervals  along  drifts,  winzes,  upraises,  shafts  and  stopes 
that  an  estimation  of  the  value  of  the  ore  in  the  mine  is  pos- 
sible. Where  the  dip  is  steep  it  is  more  convenient  to  use 
the  longitudinal  section,  because  the  levels  on  the  plan  would 
be  too  close  together  to  allow  the  figures  to  be  distinct,  but  the 
horizontal  projection  is  more  generally  used  because  the  samp- 
ling follows  the  irregularities  of  the  vein  which  do  not  appear 
on  the  longitudinal  section.  The  best  projection,  however, 
is  that  of  the  vein  itself. 

Various  terms  are  used  in  stating  the  amount  of  ore  in 
a  mine.  Practice  varies  so  much,  however,  that  it  is  not  for 
such  a  paper  as  this  to  review  what  is  recommended  in  different 
mining  sections.  The  recent  edition  of  "The  Sampling  and 
Estimation  of  Ore  in  a  Mine"  by  T.  A.  Rickard  ?s  suggested 
for  a  careful  study  of  recent  practice. 

The  following  terms  are  defined  by  various  writers: 

Ore  developed,  —  that  which  is  accessible  for  measurement, 
sampling  and  full  examination  on  all  sides. 

Ore  developing,  —  ore  exposed  on  one  side,  on  two  sides, 
or  on  three  sides. 

Ore  expectant,  —  that  which  will  probably  be  exposed  in 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING 


the  later  explorations  when  it  has  been  shown  that  the  ore 
shoot  is  of  fairly  uniform  dimensions  and  value. 

To  enter  into  actual  calculations  a  block  of  ore  must  be 
exposed  on  three  sides.  When  exposed  on  three  sides,  if  the 
ore  body  is  fairly  regular,  the  extremities  of  the  lines  not  con- 
nected may  be  considered  as  the  limits  of  the  ore  and  a  plane 
projected  through  these  points.  When  cut  on  only  two  sides, 
again  a  line  may  be  drawn  inclosing  the  triangle  and  the  ex- 
cluded ore  body  taken  as  probable  ore.  The  calculations  are 
based  on  the  theory  of  averages.  The  geometrical  mean  is 
determined  for  thickness  of  vein  and  value  of  the  ore  in  ounces. 
The  so-called  foot-ounce  method  is  thus  developed.  That  is, 
suppose  samples  be  taken  as  follows: 

Width  Assay  Foot — ounces 

4.4  feet  2.35  oz.  per  ton  10.34 

6.2  feet  .45  oz.  per  ton  2.79 

7.6  feet  .62  oz.  per  ton  4.71 

4.0  feet  .80  oz.  per  ton  3.40 

"2272  feet  TT27  oz.  per  ton  2~T724 

The  assay  per  foot  of  width  is  .96  oz.  per  ton.     This  method 

may  be  applied  to  any  number  of  samples,  samples  being  taken 

a  uniform  distance  apart.     This  method  has  been  worked  out 

by  calculus  and  demonstrated  by  Mr.  Hoffman.* 

In  the  calculation  for  tonnage  the  cubic  feet  of  ore  are 
converted  into  tons  on  the  basis  of  a  certain  specific  gravity. 
It  is  well  to  determine  the  specific  gravity  of  a  large  sample 
of  ore  and  determine  the  number  of  cubic  feet  necessary  to 
make  a  ton  of  ore,  instead  of  guessing  the  number  of  cubic 
feet  to  the  ton.**  The  summation  of  the  tonnage  in  the  num- 
erous blocks  of  ore  will  give  the  total  tonnage  in  the  mine. 
NUMBER  OF  CUBIC  FEET  PER  TON 


MATERIAL 

Number  of  Cubic  Feet  of 
Solid  Material   in    Place  Per 
Ton  of  2,000  Pounds 

Theoretical  figure 
calculated  from  the 
average  specific 
gravity  (for  pure 
unad'lt'd  spec'i'ns) 

A  Figure 
for  Practical 
Use 

Galena   ..^-      ^'°     * 

4.3  cu.  ft. 
6.4 
8.0 
6.6        ' 
8.4 
11.4        ' 
11.9        ' 
11.9 
12.3 
10.7        ' 
11.1 
11.4 

4.7  cu.  ft. 
7. 
8.5 
7.5 
9.4        " 
12.5 
13.6 
13.5 
14.5 
12.2 
12.5        " 
12.9        " 

Pyrite    .  .  &  •».  .  .  ./.'*  .f^r  
Blende       M7-7  £*    /.     -£JC~" 

Hematite  ..../  ..%.".  /trS^  
Limonite   b  (>.•&•.   ?/..  .  .Cffr.  

Limestone    Andesite     Syenite               

Vein  Quartz  Granite  and  Granite  Rocks 

Clay,  Quartz,  Porphyry,Trachytes,Rhyolites,etc. 
Vein  Quartz  with  15%  Galena         

Vein  Quartz  with  15%  Pyrite 

Vein  Quartz  with  10%  Hematite.  .  . 

*"The  Sampling-  and  Estimation  of  Ore  in  a  Mine." 

**From  "The  Sampling  and  Measurement  of  Ore  Bodies  in  Mine  Examinations,' 
by  Edmund  B.  Kirby. 


46  A  STUDY  OF  MINE  SUJtl'EYI.VG  METHODS 

The  tonnage  of  coal  in  a  tract  may  be  similarly  estimated, 
it  being  unnecessary  to  consider  the  analysis  of  the  coal.  As 
a  rough  approximation  one  thousand  tons  is  estimated  for  each 
foot  of  thickness  per  acre  for  a  horizontal  bed.  The  specific 
gravity  of  the  coal  should  be  considered  when  accurate  figures 
are  desired. 

"Loose  ore  piled  on  dumps  in  pieces  from  head  to  gravel 
size  will  have  from  35%  to  50^  of  interstitial  spaces,  the  per- 
centage being  greatest  if  the  lumps  are  somewhat  equal  sized. 
Thus  a  dump  with  40%  of  spaces,  and  composed  of  ore  averag- 
ing 12.7  cubic  feet  per  ton  in  place,  will  measure  21.2  cubic  feet 
per  ton.'** 

The  mining  engineer  may  be  called  to  direct  underground 
operations  of  various  kinds  and  in  almost  every  instance  careful 
and  successful  work  depends  in  a  measure  upon  good  surveying 
and  mapping.  Tunnels  for  water  works,  submarine  tunnels, 
submarine  pipe  lines,  etc.,  call  for  good  maps  and  generally  the 
mining  man  is  called  upon  to  do  the  work. 

Such  varied  work  requires  careful  application  to  duty  and 
attention  to  details  which  are  often  neglected  in  surface  work. 

-O      k    \&*£>^  ^BIBLIOGRAPHY. 

VA  ~*J 

TEXT  BOOKS  ON  SURVEYING. 

Brough — "Mine  Surveying." 

Carhart— "Plane  Surveying.*'     Chap.  VIII. 

Davies— "Surveying  and  Leveling.**     Book  X.  Sec.  Ill,  IV. 

Johnson — "Theory  and  Practice  of  Surveying."  Chap.  XI. 

Lupton— "A  Practical  Treatise  on  Mine  Surveying.** 

Nugent — "Plane  Surveying.**     Chap.  X. 

Raymond — "Plane  Surveying.**     Chap.  XII. 

Scott  and  others — "Mine  Surveving  Instruments."  T.  A. 
I.  M.  E. 

PERIODICALS. 
Abbreviations — 

A.  I.  M.  E. — Transactions  of  the  American  Institute  of 
Mining  Engineers. 

A.  S.  C.  E. — Transactions  of  the  American  Society  of  Civil 
Engineers. 

Coll.  Eng.— Colliery  Engineer. 

Col.  S.  S. — Proceedings  of  the  Colorado  Scientific  Society. 

E.  &  M.  J. — Engineering  and  Mining  Journal. 

M.  &  M.— Mines  and  Minerals. 

Min.  Rept. — Mining  Reporter. 

S.  of  M.  O.— School  of  Mines  Quarterly. 

*~Tbe  Sampling  and  Measurement  «rf  Ore  Bodies."  Kirby.  Col.  S.  SL.  Dec.  S.  1S86, 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING 


REFERENCES. 


Base  Line — 

Establishing  underground 
base  line, 

Bobs- 
Kind  and  weight  of, 


Coll.  Eng.  Vol.  XIV,  92. 
S.  of  M.  Q.  Vol.  XI,  333. 


Coll.  Eng.  Vol.  XVI,  31. 
S.  of  M.  Q.  Vol.  XI,  333. 
Carrying  Meridian  into  Mine — 

See  Connections,  Plumbing,  and  Shafts. 
Connections — 
Underground,  at  Leavenworth,  A.  I.  M.  E.  Vol.  XXIV,  25. 

Through  two  or  more  shafts,  Coll.  Eng.  Vol.  XVI,  53. 
Curves — 

On  mine  roads, 
Depth  of  Shaft- 
Measuring, 
Inclined  Shafts — 

Corrections  for  errors  in. 

Measuring  through  crooked 
shafts  with  plumb  line, 

Surveying,  without  attached 

telescope, 
Lamp — 

Improved  form  of  plummet, 
Plumbing,  of  Shafts, 

Hoosac  tunnel  method, 

Comstock  Lode  method, 

Montana  method, 

Croton  Aqueduct  method, 


M.  &  M.  Vol.  XXIII,  280. 
Coll.  Eng.  Vol.  XVI,  53. 
M.  &  M.  Vol.  XIX,  433. 
S.  of  M.  Q.  Vol.  XVI,  146. 
Coll.  Eng.  Vol.  XVI,  31. 
A  I.  M.  E.  Vol.  Ill,  39. 


Severn  Tunnel  method, 
Sperry  method, 
Tamarack  shaft, 
In  iron  mines  in  Pa., 
General  methods, 


Stations — 
In  poor  roof, 

Surveying  Methods — 
General, 

In  coal  fields  of  Pa., 
In  iron  mines  of  Va., 
In  the  Rocky  Mountains, 


Coll.  Eng.  Vol.  XVI,  52. 
E.  &  M.  J.  Vol.  LV,  81. 
E.  &  M.  J.  Vol.  LV,  79. 
A.  S.  C.  E.  Vol.  XXIII,  22. 
S.  of  M.  Q.  Vol.  Ill,  272. 
A.  I.  M.  E.  Vol.  XXIV,  29. 
M.  &  M.  Vol.  XXII,  247. 
A.  I.  M.  E.  Vol.  VII,  139. 
A.  I.  M.  E.  Vol.  XXI,  792. 
E.  &  M.  J.  Vol.  LXXIV,  478. 
E.  &  M.  J.  Vol.  LX'XV,  749. 
Coll.  Eng.  Vol.  XIV,  92. 
Coll.  Eng.  Vol.  XVI,  31. 
M.  &  M.  Vol.  XIX.  187. 

M.  &  M.  Vol.  XIX.  247. 

Coll.  Eng.  Vol.  XIV,  10,  etc. 
Coll.  Eng.  Vol.  XIV,  197,  etc. 
A.  I.  M.  E.  Vol.  XX,  96. 
M.  &  M.  Vol.  XIX,  241. 


/*  A  STUDY  OF  MINE  SURVEYING  METHODS 

Telescope- 
Adjustment  of  side,  A.  I.  M.  E.  Vol.  XXIV,  28. 

Volume — 

Measurement  of  stopes,  Col.  S.  S.  Dec.  3,   1895. 

Of  small  drifts  and  stopes,       M.  &  M.  Vol.  XXI,  344. 

Wires- 
Kind  and  size  of  wires,  Coll.  Eng.  Vol.  XVI,  32. 
S.  of  M.  Q.  Vol.  XI,  333. 

Illuminating,  Coll.  Eng.  Vol.  XIV,  92. 

Coll.  Eng.  Vol.  XVI,  32. 

Inspection  of  wires,  Coll.  Eng.  Vol.  XIV,  92. 

Location  of  four  or  more,     Coll.  Eng.  Vol.  XIV,  92. 
Prevention  of  vibration,  S.  of  M.  Q.  Vol.  Ill,  271. 

Coll.  Eng.  Vol.  XVI,  31. 
Suspension  of  wires,  Coll.  Eng.  Vol.  XIV,  92. 

PROBLEMS. 

The  following  are  suggested  in  order  to  teach  the  student 
graphical  and  trigonometric  methods  for  solving  mine  survey- 
ing problems. 

Problems  involving  descriptive  geometry  to  determine  the 
intersections  of  veins,  the  location  of  openings  to  cut  intersec- 
tions of  veins  and  to  locate  openings  when  veins  are  faulted. 

In  all  cases  certain  assumptions  must  be  made: 

a.  Except  in  problems  4  and  8,  the  surface  is  assumed  to 
be  a  horizontal  plane. 

b.  Veins  are  assumed  to  be  planes  of  uniform  dip.  Intersec- 
tions of  veins  are  assumed  to  be  straight  lines.     Except  in  "b" 
of  Prob.  3,  thickness  of  veins  is  not  considered. 

c.  Shafts  on  veins  will  be  straight  but  inclined. 

d.  Except  where  the  grade  is  specified  tunnels  are  assum- 
ed horizontal,  also  drifts. 

e.  Dimensions  of  shafts  and  tunnels  should  not  be  con- 
sidered, that  is,  openings  are  considered   to  be  straight  lines. 

f.  All  inclined  shafts  to  be  the  shortest  possible  except 
in  Prob.  8. 

In  the  solution  of  important  problems  found  in  practice, 
the  scale  used  should  be  such  that  the  errors  of  plotting  do  not 
materially  change  the  results. 

PROBLEM  i. 

a.     Locate  vertical  shaft  on  line  "a-b"  to  cut  the  intersec- 
tion of  veins.     Find  depths  of  shaft  and  distance  on  "a-b"  from 
A  . 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING       49 

PROBLEM   I. 

b.  At  300'  from  "A"  on  "a-b"  is  a  vertical  shaft  200'  deep. 
Find  pitch  of  inclined  shaft  and  distance  on  incline  from  bottom 
of  shaft  to  intersection  of  veins. 

Draw  to  scale  i"=3Oo'.     Take  ground  line  E  and  W. 

PROBLEM  2. 

a.  Locate  vertical  shaft  to  cut  intersection  of  veins.     Find 
depth  of  shaft  and  the  distance  and  bearing  of  point  to  sink, 
from  "o". 

b.  At  "o"  vertical  shaft  is  sunk  to  cut  vein  EF.     From 
this  point  inclined  shaft  is  sunk  on  EF  to  cut  intersection  of 
the  three  veins.     Find  depth  of  vertical  shaft,  also  bearing  and 
length  of  incline,  also  the  pitch  of  inclined  shaft. 

Draw  to  scale  i"=3Oo'.  Take  strike  of  "a-b"  as  ground 
line. 

PROBLEM  3. 

a.  Locate  by  distance  from  "o"  point  on  "a-b"  to  sink 
shaft.     This  shaft  inclined  and  the  shortest  possible  to  cut  in- 
tersection of  veins.     Find  length,  pitch,  and  bearing  of  shaft. 

b.  Call  intersection  "r".     Part  bounded  by  "xor"  is  ore. 
Taking  "xor"   as   mean   section   and   6'   as   average   thickness, 
compute  No.  tons  of  ore.     Heaviness=i7o  pounds  per  cu.  ft. 
Find  length  of  "or"  "xr". 

Draw  to  scale  i"=3oo'.     Take  strike  of  "cd"  as  G. 

PROBLEM  4. 

a.  Horizontal    distance      from      tunnel      mouth.      (Eleva- 
tion 9653'),  to  outcrop  of  vein,  (Elevation   ii745'9),  is  6000'. 
Vein  strikes  X  30°  E  and  clips  63°  to  the  N\V.     Tunnel  is  driv- 
en  N   25°W  horizontal.     Find   length   of   tunnel   to   cut   vein. 
What  depth  on  vein,  will  tunnel  cut  vein,  knowing  that  1700'  NE 
from  outcrop  elevation  is  I2345'.9'  and  taking  hillside  as  plane 
of  the  three  points  given. 

b.  Same  as  "a"  tunnel  on  2.5%  grade. 

Draw  to  scale  i"=2OOo'.o.     Take  G  E  &  W. 

PROBLEM  5. 

a.  Locate  vertical  shaft  on  Royal  to  cut  intersection  of 
veins.     Find  depth  of  shaft  and  distance  and  bearing  of  point  to 
sink  from  "o". 

b.  Locate  incline  on  Lotus.     Find  depth,  etc.  Same  as  "a". 

c.  Locate  incline  on  Minnesota.     Find  depth,  etc.     Same 
as  "a".     Scale  i"=3oo'.     Take  G  E  &  W  through  "o". 


jo  A  STUDY  OF  MINE  SURVEYING  METHODS 

PROBLEM  6. 

a.  On  the  Lotus  200'  N  W  from  "o"  an  inclined  shaft  is 
sunk  300'  in  length.  From  the  bottom  of  shaft  a  drift  extends 
on  vein  N  75°  W.  At  what  distance  from  shaft  should  a  cross- 
cut be  started  to  cut  intersection  of  Royal  and  Minnesota.  This 
crosscut  to  be  at  rt.  angles  to  drift.  Find  length  of  crosscut. 

Draw  to  scale  i"=3Oo'.     Take  G  E  &  W  through  "o". 

PROBLEM  7. 

a.  Locate  vertical  shaft  to  cut  intersection  of  veins.     Find 
bearing  and  distance  from  "o". 

b.  Vertical  shaft  is  sunk  at  x'  to  depth  of  shaft  in  "a". 
At  bottom  of  shaft  crosscut  is  run  to  cut  the  intersection  of 
veins.     Find  bearing  and  length  of  crosscut. 

c.  Incline  started  at  x'  to  cut  intersection  of  veins.     Find 
length,  pitch  and  bearing. 

d.  Locate  inclines  on:     Gopher,  Mt.  Boy  and  Yuma,  to 
cut  intersection  of  veins.     Find  lengths,  distances  and  bearings 
from  "o".  * 

Draw  to  scale  i"=3oo'.  Take  G  E  &  W  through  "o". 
Point  x'  is  300'.  N  30°  W  from  "o". 


PROBLEM  8. 


a.  From  "o"  outcrop  bears  N  10°  E  and  dip  of  vein  is  45*. 
800'  up  the  hill  the  point  "o*'  has  an  elevation  300'  higher  than 
"o".     Find  strike  of  vein. 

b.  From  "o*'  shaft  is  sunk  on  vein.     From  "o"  tunnel 
is  driven  on  vein.     Find  point  of  intersection  and  lengths  of 
shaft  and  tunnel.  .  Shaft  perpendicular  to  outcrop. 

Draw  to  scale  i"=3Oo'.     Take  G  E  &  W. 


PROBLEM  9. 

a.  Find  point  to  sink  by  bearing  and  dist.  from  "o"  to 
cut  intersection  of  veins.     Call  point  "x".     Find  depth. 

b.  At  "x",  due  west  of  "o"  5100',  S  67°  45'  W  7850'  from 
"o"  vertical  drill  holes  are  put  down  cutting  a  fault  plane  at: 
1000',  600',  looo'  ,  resp.     It  has  been  determined  that  portion 
above  fault  plane  has  moved  perpendicular  to  strike  in  a  south- 
easterly direction  along  fault  plane  500'.     Find  point  to  sink 
as  in  "a".     Faulting  took  place,  then  country  eroded  to  present 
level  condition. 

Draw  to  scale  i"=3OOo'.     Take  G  E  &  W  through  "o." 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING      57 

PROBLEM  10. 

a.  On  intersection  of  Pilot  and  Mary  inclined  shaft  is  down 
600'.  On  intersection  of  Orphan  No.  i  and  Orphan  No.  2 
inclined  shaft  is  down  550'.  As  the  air  in  both  places  is  bad,  we 
wish  to  start  an  inclined  upraise  from  one  shaft  to  connect  with 
the  other;  this  connection  to  be  the  shortest  possible.  Locate 
points  in  both  shafts  so  work  may  be  carried  on  at  both  ends. 
Find  length,  pitch  and  bearing  of  the  connection.  Reverse 
\  traces  on  Orphan  i  and  2.  Compare. 

Draw  to  scale  i"=:3oo'.     Take  G  E  &  W  through  "o". 
PROBLEM  ii. 

y 

A  vein  dips  60°,  an  entry  js  driven  N  40°  W  in  the  vein  on  a 
5%  grade.  What  is  the  strike  of  the  vein? 

PROBLEM  12. 

A  drift  on  a  3%  grade  is  driven  N  40°  E  in  a  vein  whose 
strike  is  N  60°  E.  Required  the  dip  of  the  vein. 

PROBLEM  13. 

A  vein  dips  45°  to  the  west  and  strikes  N  i2°3o'  E.     A  drift 
A      on  the  vein  is  driven  N  i6°3o'  E.     Required  the  grade  of  the 
drift. 

PROBLEM  14. 

A  vein  dips  54°  to  the  east  and  strikes  N  i8°45'  W-  What 
is  the  bearing  of  a  drift  on  the  vein  driven  on  a  3%  grade? 

PROBLEM  15. 

I.  The  strike  of  a  vein  dipping  to  the  S.  W.  75°  is  S  45°  15' 
E.  From  a  given  point  of  outcrop,  elevation  3629.4'  the  mouth 
of  a  tunel  bears  S  40°  10'  W  and  distant  3000'  on  a  vertical 
angle  of  -2i°oS^  The  tunnel  is  driven  straight,  horizontal  and 
N  I2°i5/  E.  '/^Required  the  distance  from  the  mouthy  of  the 
tunnel  to  the  point  at  which  it  intersects  the  vein.  -£L3  Assume 
the  tunnel  on  a  2%  grade.  iHJ'-What  is  the  shortest  distance 
from  the  tunnel  portal  to  the  vein?  '/  '^*- 

PROBLEM  16. 

A  vein  (a)  dips  55°  to  the  northwest  and  strikes  N  35°  !o'  E. 
A  second  vein  (b)  strikes  N  35°  10'  E  and  on  the  surface  (assum- 
ed to  be  level)  is  distant  from  the  (a)  vein  800'.  How  far  from 
the  vein  (a)  should  a  vertical  shaft  be  put  down  to  pierce  the 
intersection  of  the  veins  (i)  if  (b)  dips  30°  to  the  northwest  ;  (2) 
if  (a)  dips  75°  to  the  southeast  and  (b)  55°  to  the  northwest. 
What  will  be  the  depth  of  shaft  in  all  cases? 


ss* 


52  A  STUDY  OF  MINE  SURVEYIXG  METHODS 


PROBLEM  17. 

A  vein  dips  43°  to  the  northwest,  strikes  N  33°  15'  E,  eleva- 
tion of  outcrop  914.6'.  At  an  elevation  of  869.2'  and  distant 
from  the  outcrop  1000',  an  inclined  shaft  dipping  75°  and  bear- 
ing N  56°45'  W  is  sunk  to  intersect  the  vein,  (a)  Required  the 
depth  to  which  the  shaft  must  be  sunk,  (b)  Assume  the  pitch 
of  the  shaft  the  same  but  the  bearing  S  89°  14'  W;  what  will  be 
the  depth  of  shaft? 

PROBLEM  18. 

The  surface  has  a  uniform  slope  of  10°  to  the  north.  A 
vein  strikes  east  and  west  and  dips  40°  to  the  north. 

(a)  How  far  north  of  the  outcrop  must  one  go  to  sink  a 
vertical  shaft  which  shall  cut  the  vein  at  a  depth  of  700'.  (b) 
What  will  be  the  bearing  of  drifts  on  the  vein  driven  from  the 
bottom  of  the  shaft  on  a  3%  up  grade?  (c)  How  far  can  they 
be  driven  so  as  not  to  approach  nearer  than  100'  to  the  surface? 

PROBLEM  19. 

The  vein  described  in  problem  18  is  intersected  at  a  depth 
f<-.  JOQO'  by  a  vertical  shaft.  From  the  bottom  of  the  shaft  a 
slope  on  the  vein  extends  due  north  600'.  An  entry  is  driven 
on  a  4%  grade  to  the  southwest  from  the  bottom  of  the  slope 
for  a  distance  of  4000'.  Required  the  depth  of  vertical  shaft 
necessary  in  order  to  connect  the  end  of  the  entry  with  the 
surface? 

PROBLEM  20. 

The  horizontal  distance  between  two  vertical  shafts  is  1000', 
the  difference  in  elevation  of  the  collars  of  shafts  is  ^291. 4'.  The 
depth  of  shaft  sunk  from  the  higher  point  is  647.2' ;  from  the 
bottom  of  this  shaft  a  crosscut  (a)  is  driven  towards  the  other 
shaft  on  a  i%  grade,  436'.  The  second  shaft  is  350'  deep.  Re- 
quired the  length  and  grade  of  crosscut  (b)  from  this  shaft  to 
meet  the  breast  of  (a). 

fyVr^--^  . 

PROBLEM  21. 


Suppose  that  the  lower  shaft  described  in  20  bears  S  i9°4o' 
W  of  the  other  and  that  the  crosscut  (a)  is  driven  S  40°  W.  Re- 
quired the  direction,  grade  and  length  of  (b). 


AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING      jj 

PROBLEM  22. 

A  vein  dips  60°  to  the  south  and  strikes  N  70°  E.  Consider 
the  outcrop  of  the  vein  as  3650'  elevation.  500'  distant  from 
the  outcrop  and  at  an  elevation  of  360 i'  a  vertical  shaft  is  sunk 
to  intersect  the  vein.  From  this  shaft  the  mouth  of  a  crosscut 
tunnel  bears  S  60°  E,  2000'  on  a  vertical  angle  of  —  30°.  The 
tunnel  is  driven  N  33°  W  on  a  2%  grade  to  intersect  the  vein. 
Required  the  length  of  slope  on  the  vein  necessary  to  connect 
the  shaft  and  the  tunnel. 


PROBLEM  23. 

Using  the  top  telescope: 

(a)  Elevation=876.42' 
+V.  A.=52°29' 

M.  0=76.49' 
— H.  1=  2.58' 
+H.Pt=  3.45' 
r=     .301' 

M.  D=Distance  from  axes  of  main  telescope  to  point 
of  sight. 

Required  V.  D.,  H.  D.  and  elevation. 

(b)  Elevation=76i .  59' 
-V.  A.=69°55' 

M.  D.=87.23' 
+H.  I.=  4.28' 
— H.  Pt==  3.91' 
r=  .301' 

Required  V.  D.,  H.  D.  and  elevation. 

(c)  Elevation  back  sight  station=647.9i' 
Backsight          +V.  A.=59°2o' 

M.  0=63.48' 
— H.  I.=  4.21' 
-H..  Pt=  3.19' 

r=     .301' 

Foresight          —V.  A.=57°i9' 

M.  D.=56.93' 

+H.  Pt=  3.21' 

Required  elevationl  of  foresight  station. 


3V  A  STUDY  OF  MINE  SURVEYING  METHODS 

PROBLEM  24. 

Using-  the  side  telescope: 

Elevation  of  backsight  station  426.81' 

Backsight          +V.  A.=46°2i' 

+H.  Pt=  3.19' 

vernier  I9°24' 

+H.  I.=  2.26' 

M.  D.=98.23' 

Foresight  +  Vernier  (angle  right)=T76°48' 

_V.  A.=s6°48/ 
+H.  Pt=  4.16' 
M.  0—76.24' 

Required  elevation  of  new  station. 

PROBLEM  25. 

,  t™      ' 

It  is  impossible  to  place  staging-  in  a  shaft  and  the  second 
level  is  not  visible  from  the  first  level.  In  order  to  save  time 
underground,  three  points  in  the  shaft  visible  from  both  levels 
are  established.  The  following  notes  are  taken  (using  the  top 
telescope)  : 

Sta.  Pt.  Az.  M.  D.  V.A.  H.I. 

100          100  a        298°  35-04'        —  89°2o'         3.  91' 


3-69' 


a-  C.  --  C. 

Required  the  distance  and  bearing  of  200  from  100. 


ioo  a 
100  b 

TOO    C 

ioo  a 
ioo  b 

IOO   C 
O.-fr' 

298° 

202°32' 

237^0' 
297°i8; 

35-04' 
37-74' 
36-58' 
54-43' 
51.82' 

53-13- 

—  89°2o' 
—  87°4i' 
—88°  10' 

+54>V 

+53°o6' 

AND  THEIR  APPLICATIONS  TO  MINING  ENGINEERING 


© 


TABLE  OF  CONTENTS 


PAGE 

Introduction 3 

Definitions . .    . 3 

Importance  of  Mine  Surveying 4 

Difficulties 5 

Notes  on  History  of  Mine  Surveying 6 

Instruments  and  Equipment  Used 6 

Surveying  Party 1 1 

Underground  Stations ..12 

Base  Line 22 

Carrying  the  Level  and  Meridian  Into  the  Mine ...    23 

Underground  Traversing 29 

Surveying  the  Mine 31 

Geognosy 33 

Surveying  Drill  Holes 34 

Locating  Openings  and  Mine  Plant 35 

Shaft  Sinking. . 36 

Tunneling 37 

Mine  Workings 38 

Curves  and  Connections 38 

Openings  to  Intersect  Veins 39 

Geological  Irregularities 40 

Drainage 40 

Haulage 41 

Mapping  and  Models 41 

Calculation  of  Volumes  and  Assay  Plans 43 

Problems 48 

Bibliography 46 


Date  Due 


JUN    7  1977 


JUN    31977 


The  RALPH  D.  REED  LIBRARY 

DEPARTMENT  OF  OEOLOGY 

UNIVERSITY  of  CALIFORNIA 

LOS  ANGELES.  CALIF. 


uNiYERsrnrLoF  CALIFORNIA 

LOS  ANGELES 


UCLA-Geology/Geophysic, 


Library 


TN273Y85S 
006  578  009  0 


